The redesigned second generation Ford Expedition was developed under the U222 program code name. The new Expedition was introduced in 2002 for the 2003 model year and featured an all-new 4-wheel independent suspension, becoming the first full-size body-on-frame sport utility vehicle to use a fully independent suspension system. The new multi-link independent rear suspension (IRS) reduced rear unsprung mass by 110 pounds, improving the suspension’s wheel travel and ability to track uneven terrain and road surfaces for improved control and ride quality. The new IRS was perceived as being controversial by some at the time of its introduction. A misconception was that the Expedition’s towing and off road capabilities would be reduced, in comparison to the previous generation’s rear live axle. Nevertheless, the Expedition’s ground clearance improved by 1.4& inches for a total of 8.9& inches. Towing capacity increased by 800& lbs (363& kg) for a high towing capacity of 8,900& lbs (4,037& kg) when properly equipped with the appropriate axle ratio and heavy-duty trailer tow package. Payload capacity was increased up to 1,614& lbs (732& kg). Expedition also gained a hydroformed fully boxed frame providing a 70 percent improvement in torsional stiffness.

Along with the high towing capability came all-new steering, braking and electronic systems to help the Expedition better control and maneuver long heavy trailers. Adaptive variable assist power rack-and-pinion steering was introduced along with the largest brake rotors in the segment at that time (13& inches up front, 13.5& inches in back) with brake calipers 100 percent stiffer than the previous generation Expedition. The 4-speed 4R70W automatic transmission received all-new control software to allow the transmission to automatically adjust to the demands of towing, using new computer logic that recognizes changes in load and road conditions.

2 High mode was reintroduced on the available ControlTrac 4-wheel-drive system with Auto, 4 High (lock) and 4 Low (lock) modes. The transfer case use in the first generation was replaced by an updated unit (BorgWarner model: 4416). A new dedicated microprocessor along with new control software were added allowing the system to detect different terrain and surface conditions to predict traction loss before it happened.

The V8 engines offered on the previous generation were carried over, but not without major changes and improvements. Both the 4.6 and 5.4 liter Triton V8 engines received further refinements in design and overall efficiency. Expedition qualified as an Ultra Low Emission Vehicle (ULEV) and was certified under the Environmental Protection Agency Tier 2 regulations one year earlier than required. The 4.6 liter engine received an all-new redesigned cast aluminium engine block optimized for weight reduction and NVH improvements. The 5.4 liter engine received an all-new redesigned cast iron engine block with computer designed ribbing and bracing, along with thicker side skirts and reinforcement at the oil pan flange. The new engine block helped reduce engine vibration and unwanted noise while providing refined performance.

Both engines featured piston skirts coated with a teflon based friction reducing material, and fitted with low tension, low oil consumption rings. In addition, a new fail-safe cooling mode provided protection even in the case of a catastrophic coolant loss (such as a punctured radiator). In the event of coolant loss, the engine control unit shuts off fuel to alternate cylinders to reduce the risk of engine damage from overheating. The valves continue to operate, in order to pump cooling air through the cylinders. The cooling system was designed to maintain an ideal engine temperature even when subjected to a prolonged 15 percent gradient in 46°C (115°F) weather. A returnless fuel supply system helped to reduce evaporative emissions by providing consistent pressure to the fuel injectors through a high-pressure pump.

New active hydraulic engine mounts were introduced to prevent the powertrain from inducing vibrations into the chassis. By optimizing these engine mounts the engine block can act as a mass damper, absorbing chassis resonance, improving ride comfort.

Expedition’s passenger cabin was better sealed than before, in an effort to eliminate intrusive outside noise from reaching the occupants. Wind, powertrain, road and vehicle body noise was reduced by improving interior acoustics through new damping materials, a total of 10 shear-style isolating body mounts, heavier sealing of body and panels, redesigned rubber door seals, and extensive use of interior structural acoustic foam in the upper B-pillars, upper and lower D-pillars and floor pan. Road noise was reduced by 2 decibels, body air leakage reduced by 56 percent, chances for sealant noise disturbances reduced from 15 percent to less than 0.5 percent and wind noise measured at 80& mph was reduced from 35 sones to a world class level of 29 sones.

The Expedition also received a thorough exterior and interior cosmetic redesign. Expedition featured an all-new front fascia, grille work, headlamps, body trim, rear fascia, tail lamps and liftgate. Interior fit & finish were improved with a all-new interior featuring new dash, door panels, genuine aluminium trim, and plush carpeting. Premium perforated leather seating surfaces were standard on Expedition ”Eddie Bauer” (optional on Expedition ”XLT”). Expedition ”FX4” models featured all of Expedition’s optional off road equipment as standard equipment. Expedition’s drag coefficient was 0.41 Cd.

Three row seating was standard with all-new manual fold-flat stow away third row seats. No longer did owners have to remove the third rows seats for more storage. The third row could simply “disappear” into the floor. Power assisted PowerFold™ fold-flat third row seating was available as an optional extra. Available features included in-dash CD-ROM based navigation system, DVD based rear entertainment system, ultrasonic rear park assist/back up sensors, power moon roof, power adjustable accelerator and brake pedals (introduced on the first generation Expedition), Gentex auto dimming electrochromatic rear view mirror, rearward facing lane departure/turning indicator lamps on side view mirrors, second row captains chair luxury seating, premium Audiophile™ sound system with in-dash 6-disc CD changer and rear subwoofer and 4-wheel independent adaptive electronically controlled pneumatic suspension system.

Engine(s)

Transmission(s)

Safety and security

Like the generation before, a 2-air bag supplementary restraint system (SRS) with 2-way occupant protection was standard on Expedition. Adaptive dual front air bags for front seat occupants now included the Personal Safety System™ (PSS). PSS would tailor air bag deployment for driver and first passenger and included occupant classification, seat position, crash severity, safety belt pretensioner, load limiting retractor and safety belt buckle usage sensors.

An optional 4-air bag supplementary restraint system (SRS) with 6-way occupant protection was also available. This new protection system included the new SafetyCanopy™ head, upper torso and rollover protection side curtain air bags which would deploy along the A, B and C-pillars down to the vehicle’s belt line. SafetyCanopy could remain inflated after deployment for extended protection. SafetyCanopy replaced the front seat side impact air bags featured on the first generation Expedition.

Other features included side intrusion door beams, security approach lamps, SecuriLock with smart key and engine immobilizer, BeltMinder™, three-point safety belts for all rows of seating, post crash fuel pump shut-off, tire pressure monitoring system (TPMS) and 4-wheel ABS with electronic brakeforce distribution (EBD) and emergency brake assist (EBA). AdvanceTrac™ was introduced as a optional extra and included both electronic traction control and electronic stability control (ESC). The electronic traction & stability mitigation system would expand to include ”roll stability control” (RSC) for the 2005 model year.

Model year changes=

2003

Oddly, before the 2003 model year ended Ford updated the running boards on Expeditions equipped with the Eddie Bauer trim. Earlier in the model year, Eddie Bauer models had received standard black running boards. Toward the end of the model year, Arizona beige running boards were introduced to complement the Arizona beige body work which came standard on Eddie Bauer. Body colored running boards had previously been offered on the first generation Expedition from 2000-2002.

2004

No major cosmetic or mechanical changes. The Expedition ”Eddie Bauer Premier” model is reintroduced after being absent from the 2003 model trim line-up. Monochromatic paint work with blacked-out headlamps and special alloy wheels were standard on Eddie Bauer Premier versions. A new Expedition ”XLT Sport” model is added with Dark Shadow grey exterior body trim. The ”FX4” trim level was renamed ”NBX”.

2005

Expedition received new roof rails which replaced the traditional sliding cross-bar roof racks. A new high end ”Limited” trim level replaced the Eddie Bauer Premier model (though the regular Eddie Bauer was still available) and featured chrome accented roof rails, chrome-clad aluminium wheels, PowerFold™ power assisted stowable side view mirrors and chrome tipped exhaust. A upper high end ”King Ranch” trim level with Castano leather seating was also introduced. The base 4.6 liter Triton V8 engine was dropped for the 2005 model year as the 5.4 liter Triton V8 was made standard on all Expeditions and updated with 24-valve technology and variable valve timing. Along with the 2005 model V8 engine update, the Expedition also received a significantly updated version of the 4-speed 4R70W automatic transmission.

The new 4-speed automatic transmission, now called 4R75E featured fully electronic Smart Shift technology. A turbine speed sensor improved transmission control and provided the basis for the fully electronic shift scheduling. The transmission’s microprocessor speeds were improved for better responsiveness and precision of the control system. The transmission was continuously learning, and would calculate the torque in the next gear and schedule shift points based on the Expedition’s projected performance in the next gear. For 2005 model Expeditions the 4R75E transmission is designated by the letter “B” on the manufacturers safety compliance certification label, located in the driver’s side door jamb. For 2006 model Expeditions, the 4R75E transmission is designated by the letter “Q”.

2006

No major cosmetic or mechanical changes. Last year model for the U222. The Gentex auto dimming rear view mirrors were updated. Two new exterior colors were added later on within the model year. They were Pewter metallic and Dark Copper metallic. Medium Flint grey interior was also added to Limited models later on within the model year. Chrome tipped exhaust was made standard on King Ranch models. 2006 would be the last year model for the NBX trim. The ultrasonic rear park assist and SafetyCanopy side curtain airbags were offered as standalone options.

Russian Москва-Чукотка (Moscow-Chukotka) overland expedition

On April 12, 2006, three second generation Ford Expedition ”Eddie Bauer” full-size sport utility vehicles successfully and autonomously completed a grueling 32 day off road overland expedition. The heavy-duty 4x4s journeyed nearly 30,000 kilometres across North Asia, the arctic tundra and at times, uncharted territory. The expedition team was made up of six members (two in each vehicle) which included the expedition leaders: Alexey Mikhailov and Alexander Borodin; technical director: Andrey Rodionov and professional off road drivers: Sergey Goryachev, Victor Parshikov and Alexey Simakin. The expeditionary trip was exactly 28,000 kilometres or about 17,398 miles round trip (there and back collectively). The planned route resulted in the SUVs primarily traveling on permafrost and herded the Ford Expeditions across the Arctic Circle twice. The expeditionary team visited landmarks such as the spot where American aviator Carl Ben Eielson was lost, and the birthplace of Russian explorer Semyon Dezhnev. The northern most point on the route was latitude 69°42′ North (Pevek). The eastern most point visited was longitude 169°40’ West (Cape Dezhnev). The Ford Expeditions endured unforgiving terrain, constant frigid temperatures down to -36°C (-32°F), whiteouts and a violent polar cyclone that engulfed the expeditionary team toward the end of the expedition, resulting in the team stopping the vehicles. They remained inside the SUVs for protection during the storm’s nighttime onslaught as temperatures dropped and winds whaled against the vehicle windows. 200 kilograms (440 pounds) of snow were removed from each of the Ford Expeditions after the tail end of the storm swept across them again the following day.

The Ford Expeditions where off-the-shelf production versions equipped with the ControlTrac 4-wheel-drive system. Two of the SUVs were charged with towing dual axle utility trailers during the journey. The SUVs were lightly modified with front end guards along with front and rear utility bumpers, winches, safari roof racks, high-powered off road lights and extra belly plating for the engines. Because the trip would venture far from civilization, the vehicles were also equipped with gas stoves and high capacity auxiliary fuel tanks (mounted in the rear cargo bay) for when petrol/gas stations became nonexistent. The SUVs still retained their factory stock engines, transmissions, four-wheel-drive systems, suspensions, even their factory 17×7 alloy 5-spoke wheels. Two of the Ford Expeditions were equipped with caterpillar track systems supplied by [http://www.mattracks.com/ Mattracks]. The rubber track systems were used when off road conditions became too demanding for conventional tread tires. Whether directly or non directly related, the rear stabilizer bar failed on the two Expeditions fitted with the Mattracks system. The problem was ruled most likely to be a combination of both overloading and extreme off road conditions. While the issue was fixed and the SUVs continued on with the expedition, the Mattracks however, continued to be problematic. The 5.4 liter Triton V8 engines were sometimes forced to run on poor-quality petrol/gas from unknown sources when high-quality fuel could not be found.

Adapted from the Wikipedia article Ford Expedition, under the G. N. U. Free Documentation License. Please also see http://en.wikipedia.org/wiki

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Lighter than air – aerostats

Aerostats use buoyancy to float in the air in much the same way that ships float on the water. They are characterized by one or more large gasbags or canopies, filled with a relatively low density gas such as helium, hydrogen or hot air, which is less dense than the surrounding air. When the weight of this is added to the weight of the aircraft structure, it adds up to the same weight as the air that the craft displaces.

Small hot air balloons called sky lanterns date back to the 3rd century BC, and were only the second type of aircraft to fly, the first being kites.

Originally, a balloon was any aerostat, while the term airship was used for large, powered aircraft designs – usually fixed-wing – though none had yet been built. The advent of powered balloons, called dirigible balloons, and later of rigid hulls allowing a great increase in size, began to change the way these words were used. Huge powered aerostats, characterized by a rigid outer framework and separate aerodynamic skin surrounding the gas bags, were produced, the Zeppelins being the largest and most famous. There were still no fixed-wing aircraft or non-rigid balloons large enough to be called airships, so “airship” came to be synonymous with these aircraft. Then several accidents, such as the Hindenburg disaster in 1937, led to the demise of these airships. Nowadays a “balloon” is an unpowered aerostat, whilst an “airship” is a powered one.

A powered, steerable aerostat is called a ”dirigible”. Sometimes this term is applied only to non-rigid balloons, and sometimes ”dirigible balloon” is regarded as the definition of an airship (which may then be rigid or non-rigid). Non-rigid dirigibles are characterized by a moderately aerodynamic gasbag with stabilizing fins at the back. These soon became known as ”blimps”. During the Second World War, this shape was widely adopted for tethered balloons; in windy weather, this both reduces the strain on the tether and stabilizes the balloon. The nickname ”blimp” was adopted along with the shape. In modern times any small dirigible or airship is called a blimp, though a blimp may be unpowered as well as powered.

Heavier than air – aerodynes

Heavier-than-air aircraft must find some way to push air or gas downwards, so that a reaction occurs (by Newton’s laws of motion) to push the aircraft upwards. This dynamic movement through the air is the origin of the term ”aerodyne”. There are two ways to produce dynamic upthrust: aerodynamic lift, and powered lift in the form of engine thrust.

Aerodynamic lift is the most common, with fixed-wing aircraft being kept in the air by the forward movement of wings, and rotorcraft by spinning wing-shaped rotors sometimes called rotary wings. A wing is a flat, horizontal surface, usually shaped in cross-section as an aerofoil. To fly, air must flow over the wing and generate lift. A ”flexible wing” is a wing made of fabric or thin sheet material, often stretched over a rigid frame. A ”kite” is tethered to the ground and relies on the speed of the wind over its wings, which may be flexible or rigid, fixed or rotary.

With powered lift, the aircraft directs its engine thrust vertically downwards.

The initialism ”VTOL” (vertical take off and landing) is applied to aircraft that can take off and land vertically. Most are rotorcraft. Others, such as the Hawker Siddeley Harrier and F-35B, take off and land vertically using powered lift and transfer to aerodynamic lift in steady flight. Similarly, ”STOL” stands for short take off and landing. Some VTOL aircraft often operate in a short take off/vertical landing mode known as STOVL.

A pure rocket is not usually regarded as an aerodyne, because it does not depend on the air for its lift (and can even fly into space); however, many aerodynamic lift vehicles have been powered or assisted by rocket motors. Rocket-powered missiles which obtain aerodynamic lift at very high speed due to airflow over their bodies, are a marginal case.

Fixed-wing

”Airplanes” or ”aeroplanes” are technically called ”fixed-wing aircraft”.

The forerunner of the fixed-wing aircraft is the kite. Whereas a fixed-wing aircraft relies on its forward speed to create airflow over the wings, a kite is tethered to the ground and relies on the wind blowing over its wings to provide lift. Kites were the first kind of aircraft to fly, and were invented in China around 500 BC. Much aerodynamic research was done with kites before test aircraft, wind tunnels and computer modelling programs became available.

The first heavier-than-air craft capable of controlled free flight were gliders. A glider designed by Cayley carried out the first true manned, controlled flight in 1853.

Besides the method of propulsion, fixed-wing aircraft are generally characterized by their wing configuration. The most important wing characteristics are:

*Number of wings – Monoplane, biplane, etc.

*Wing support – Braced or cantilever, rigid or flexible.

*Wing planform – including aspect ratio, angle of sweep and any variations along the span (including the important class of delta wings).

*Location of the horizontal stabiliser, if any.

*Dihedral angle – positive, zero or negative (anhedral).

A variable geometry aircraft can change its wing configuration during flight.

A ”flying wing” has no fuselage, though it may have small blisters or pods. The opposite of this is a ”lifting body” which has no wings, though it may have small stabilising and control surfaces.

Most fixed-wing aircraft feature a tail unit or empennage incorporating vertical, and often horizontal, stabilising surfaces.

”Seaplanes” are aircraft that land on water, and they fit into two broad classes: Flying boats are supported on the water by their fuselage. A float plane’s fuselage remains clear of the water at all times, the aircraft being supported by two or more floats attached to the fuselage and/or wings. Some examples of both flying boats and float planes are amphibious, being able to take off from and alight on both land and water.

Some people consider wing-in-ground-effect vehicles to be fixed-wing aircraft, others do not. These craft “fly” close to the surface of the ground or water. An example is the Russian ekranoplan (nicknamed the “Caspian Sea Monster”). Man-powered aircraft also rely on ground effect to remain airborne, but this is only because they are so underpowered—the airframe is theoretically capable of flying much higher.

Rotorcraft

The first powered flight was made in a steam-powered dirigible by Henri Giffard in 1852. Attempts to marry a practical lightweight steam engine to a practical fixed-wing airframe did not succeed until much later, by which time the internal combustion engine was already dominant.

From the first controlled powered fixed-wing aircraft flight by the Wright brothers until World War II, propellers turned by the internal combustion piston engine were virtually the only type of propulsion system in use. (See also: Aircraft engine.) The piston engine is still used in the majority of smaller aircraft produced, since it is efficient at the lower altitudes and slower speeds suited to propellers.

Turbine engines need not be used as jets (see below), but may be geared to drive a propeller in the form of a turboprop. Modern helicopters also typically use turbine engines to power the rotor. Turbines provide more power for less weight than piston engines, and are better suited to small-to-medium size aircraft or larger, slow-flying types. Some turboprop designs (see below) mount the propeller directly on an engine turbine shaft, and are called propfans.

Since the 1940s, propellers and propfans with swept tips or curved “scimitar-shaped” blades have been studied for use in high-speed applications so as to delay the onset of shockwaves, in similar manner to wing sweepback, where the blade tips approach the speed of sound. The Airbus A400M turboprop transport aircraft is expected to provide the first production example: note that it is not a propfan because the propellers are not mounted direct on the engine shaft but are driven through reduction gearing.

Other less common power sources include:

*Electric motors, often linked to solar panels to create a solar-powered aircraft.

*Rubber bands, wound many times to store energy, are mostly used for flying models.

Jet

Air-breathing jet engines provide thrust by taking in air, burning it with fuel in a combustion chamber, and accelerating the exhaust rearwards so that it ejects at high speed. The reaction against this acceleration provides the engine thrust.

Jet engines can provide much higher thrust than propellers, and are naturally efficient at higher altitudes, being able to operate above . They are also much more fuel-efficient at normal flight speeds than rockets. Consequently, nearly all high-speed and high-altitude aircraft use jet engines.

The early turbojet and modern turbofan use a spinning turbine to create airflow for takeoff and to provide thrust. Many, mostly in military aviation, use afterburners which inject extra fuel into the exhaust.

Use of a turbine is not absolutely necessary: other designs include the crude pulse jet, high-speed ramjet and the still-experimental supersonic-combustion ramjet or scramjet. These designs require an existing airflow to work and cannot work when stationary, so they must be launched by a catapult or rocket booster, or dropped from a mother ship.

The bypass turbofan engines of the Lockheed SR-71 were a hybrid design – the aircraft took off and landed in jet turbine configuration, and for high-speed flight the afterburner was lit and the turbine bypassed, to create a ramjet.

The motorjet was a very early design which used a piston engine in place of the combustion chamber, similar to a turbocharged piston engine except that the thrust is derived from the turbine instead of the crankshaft. It was soon superseded by the turbojet and remained a curiosity.

Helicopters

The rotor of a helicopter, may, like a propeller, be powered by a variety of methods such as an internal-combustion engine or jet turbine. Tip jets, fed by gases passing along hollow rotor blades from a centrally mounted engine, have been experimented with. Attempts have even been made to mount engines directly on the rotor tips.

Helicopters obtain forward propulsion by angling the rotor disc so that a proportion of its lift is directed forwards to provide thrust.

Other methods of propulsion

*”Rocket-powered aircraft” have occasionally been experimented with, and the Messerschmitt ”Komet” fighter even saw action in the Second World War. Since then they have been restricted to rather specialised niches, such as the Bell X-1 which broke the sound barrier or the North American X-15 which traveled up into space where no oxygen is available for combustion (rockets carry their own oxidant). Rockets have more often been used as a supplement to the main powerplant, typically to assist takeoff of heavily loaded aircraft, but also in a few experimental designs such as the Saunders-Roe SR.53 to provide a high-speed dash capability.

*The flapping-wing ”ornithopter” is a category of its own. These designs may have potential, but no practical device has been created beyond research prototypes, simple toys, and a model hawk used to freeze prey into stillness so that it can be captured.

Adapted from the Wikipedia article Aircraft, under the G. N. U. Free Documentation License. Please also see http://en.wikipedia.org/wiki

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Significant SLR technology firsts (including optics peculiar to SLRs and important SLR evolutionary lines now extinct).

Pre-19th century

;1676: Johann Sturm (Germany) described first known use of a reflex mirror in a camera obscura. The camera obscura was known to Aristotle as an aid in observing solar eclipses, but its use as an artist’s aid was first expounded by Giambattista della Porta (Italy) in 1558. The reflex mirror corrected the up-down image reversal that could make using a non-SLR camera obscura disconcerting – but not the left-right reversal.

;1685: Johann Zahn (Germany) developed a portable SLR camera obscura with focusable lens, adjustable aperture and translucent viewing screen. These are all the core elements in a modern SLR photographic camera – except for an image capture medium. It would not be until 1826/27 before Joseph Nicéphore Niépce (France) made the first permanent photograph using a bitumen photosensitized pewter plate in a non-SLR camera. All advances in photographic technology since then – mechanical, optical, chemical or electronic – have been convenience or quality improvements only.

;18th century: SLR camera obscuras popular as drawing aids. Artist can trace over the ground glass image to produce a true-life realistic picture.

19th century

;1861: Thomas Sutton (UK) received first patent for SLR photographic camera. An unknown number made but very few; no known production model; no known surviving examples. The manually levered reflex mirror also served as the camera’s shutter. Used glass plates.

;1884: Calvin Rae Smith Monocular Duplex (USA): first known production SLR. Used glass plates (original model 3¼×4¼ inch, later 4×5& inch); many were adapted to use Eastman sheet film. Large-format glass plate or sheet film SLRs were the dominant SLR type until circa 1915. However, SLRs themselves were not commonplace until the 1930s. The Duplex’s name was a reference to the SLR’s one lens performing both viewing and imaging duties, in contrast to the two separate viewing and imaging lenses of the twin lens cameras (first production 1882 [Marion Academy; UK]; not necessarily twin-lens reflex [TLR] camera, invented 1880 [one-of-a-kind Whipple-Beck camera; UK]) popular in the 1880s and 90s.

;1898: W. Watson Cambier Bolton (UK): first focal-plane shutter SLR. Had synchronized mirror rise and shutter release, with speeds from 1/20 to 1/1000 second. An internal camera-mounted traveling-slit FP shutter’s main advantage over the competing interlens leaf shutter was the ability to use a very narrow slit to offer an action stopping 1/1000 second shutter speed at a time when leaf shutters topped out at 1/250 sec. – although the available contemporaneous ISO 1 to 3 equivalent speed emulsions limited the opportunities to use the high speeds.

Early 20th century

;1907: Folmer & Schwing Graflex No. 1A (USA): first medium format roll film SLR. Took eight exposures of 2½×4½ inch frames on 116 roll film. Had folding waist level finder and focal-plane shutter. A sister SLR camera, the Graflex No. 3A, was released at about the same time. It took six 3¼×5½ inch “postcard” frames on 122 roll film. Roll film (usually 120 type) SLRs became the dominant SLR type in 1930s. The various models of large and medium format Graflex SLRs made beginning in 1898, and culminating in the 4×5& inch sheet film Graflex Super D of 1948, are the best and most famous American-made SLRs, if only for the shortage of competition. Graflex quit the camera business in 1973. A-127 is the rarest and most valuable at 1254 dollars – 3400 dollars

;1925: Ernemann (merged into Zeiss Ikon, 1926) Ermanox Reflex (Germany): first SLR with high speed lens (10.5& cm f/1.8 or 85mm f/1.8 Ernostar). Established SLR as viable photojournalist’s available-light camera. Had folding waist level finder and focal-plane shutter. Used 4.5×6& cm glass plates or sheet film; adaptable to roll film.

1930s

;1933: Ihagee VP Exakta (Germany): first 127 roll film SLR. Preliminary designs were on paper by June 1932. Took eight exposures of 4×6.5& cm (1⅝×2½ inch) nominal frames (40×62& mm actual frames) on 127 “Vest Pocket” roll film, and had a folding waist level finder and focal-plane shutter. The 1935 version was the first camera with a built-in flash synchronization socket (called Vacublitz) to automatically synchronize the recently invented flashbulb (first marketed as Vacublitz in 1929) with its shutter. The VP also established the oblong body shape and handling soon to be standard in 35& mm SLRs except that Exakta SLRs had primarily left-handed controls and were more trapezoidal shaped than rectangular.

;1934: Eichapfel Noviflex (Germany): first 2¼ square format, medium format roll film SLR. Took twelve exposures of 6×6& cm (2¼×2¼ inch) frames on 120 roll film. Also had a fixed lens and focal-plane shutter. The 1937 version had interchangeable lenses. The square frame format precluded the awkward manipulations needed to take a vertical photograph with horizontal rectangular format SLRs having then standard waist-level viewfinders. The Noviflex was not commercially successful; it was the Franz Kochmann Reflex-Korelle (Germany) of 1935 that established the popularity of the 2¼ square format SLR.

;1935: 135 film, commonly called 35& mm film, introduced by Kodak (USA). Was (and is) 35& mm nominal width (1⅜ inch actual width), acetate base, double perforated film, pre-loaded into felt-lipped, daylight-loading cartridges ready-to-use for still cameras. Originally intended for Kodak Retina, Zeiss Ikon Contax and E. Leitz Leica 35& mm rangefinder cameras. Previously, bulk rolls of 35& mm motion picture film would need to be user cut and loaded, in complete darkness, into camera specific cartridges or magazines. The September 1936 release of Kodachrome (the first high speed [ISO 8 equivalent], realistic color film) in standardized 135 format (but not medium format roll film) spurred explosive growth in the popularity of all types of miniature format 35& mm cameras. The vast majority were not high-end SLRs or RFs, but basic amateur RFs such as the nearly three million selling Argus C3 (USA) of 1939. Originally, each US$3.50 (including processing) Kodachrome cartridge gave eighteen exposures if the camera used the 24×36& mm frame size (double the frame size of 35& mm cine cameras) established by the Multi-Speed Shutter Co. Simplex (USA) camera of 1914 and popularized by the E. Leitz Leica A (Germany) of 1925. The 24×36& mm frame size did not become the universal standard frame size until the early 1950s. Note that 135 film cameras using non-standard frame sizes, such as 24×18& mm or 24×24& mm, continued to be made into the early 1990s. Panoramic 135 film cameras using extra-wide aspect ratio frame sizes (up to 24×160& mm for the 360° revolving slit Globuscope [USA] of 1981) were still available in 2006.

;1936: Ihagee Kine Exakta (Germany): first production 35& mm SLR, first system SLR, first interchangeable lens camera with bayonet lens mount. This was exhibited at the Leipzig Spring Fair in March and was in production by April 1936. Had left-handed shutter release and rapid film wind thumb lever, folding waist level finder and 12 to 1/1000 second focal-plane shutter. Well-integrated design with excellent interchangeable lenses and good accessory system. Fewer than 30,000 Kine Exaktas were made before World War 2 stopped production in 1940. Production of improved models re-started after the war and Exakta was the best known 35& mm SLR brand until 1959.

;1936: E. Leitz PLOOT (Germany): first reflex housing for 35& mm rangefinder cameras. For use with a Leica IIIa RF and the Leitz 20& cm f/4.5 Telyt or 40& cm f/5 Telyt long focus lenses (all Germany). Long focus (and telephoto) lenses have very shallow depth of field and the short baseline rangefinders built into RF cameras cannot triangulate the subject distance accurately enough for acceptably sharp focusing. SLRs do not suffer from this problem, because they are focused by directly assessing the sharpness of the lens image – the lens serves as its own rangefinder. Reflex housings converted RFs into very awkward SLRs by inserting a reflex mirror and focusing screen between the lens and camera. Some even had image reversing optics. They also solved the RF camera’s parallax error problem in macrophotography. Eventually, real SLRs were recognized as the simpler solution and supplanted RFs in the 1960s. The last reflex housing, the Leica Visoflex III (West Germany), was discontinued in 1984.

;1937: Gosudarstevennyi Optiko-Mekhanichesky Zavod (GOMZ) Sport (Спорт; Soviet Union): a 35& mm (not 135 type) SLR apparently prototyped in 1935. However, sources are uncertain or conflict upon the Sport’s introduction date – a plurality say 1937. If it was sold in 1935, it would be the first 35& mm SLR. In any event, the Sport was not widely available and had no influence on later SLRs.

1940s

;1947: Gamma Duflex (Hungary): first instant return mirror SLR, first metal focal-plane shutter SLR, first internal semi-automatic lens diaphragm SLR. Also had a mirror “prism” viewfinder, an intermediate step to a solid pentaprism. Reflex mirrors coupled to the shutter release had been spring actuated to rise automatically since the 19th century, but the viewfinder would remain blacked-out until the mirror was manually cocked back down. With an automatic, instant return mirror, the viewfinder blackout time might be as short as ⅛th second. The semi-auto diaphragm closed the lens diaphragm with shutter release, but it needed to be manually re-cocked open. The Duflex was very ambitious, but very unreliable and Gamma’s first and last production SLR.

;1948: Hasselblad 1600F (Sweden): first 2¼ medium format system SLR suitable for professional use. Took twelve exposures of 2¼×2¼ inch (6×6& cm) nominal frames (56×56& mm actual frames) on 120 film. Had modular design accepting interchangeable lenses, film magazines and folding waist level finder. The 1/1600 second corrugated stainless steel focal-plane shutter was unreliable and was replaced by a slower but more reliable 1/1000 second focal-plane shutter in the Hasselblad 1000F (Sweden) of 1952.

;1948: Alpa Prisma Reflex (Switzerland) had a pentaprism viewfinder in 1948, but its eyepiece was angled upward at 45°.

;1949: VEB Zeiss Ikon (Dresden) Contax S (East Germany): first pentaprism eyelevel viewing 35& mm SLR. (The Italian Rectaflex Standard came very soon after.) First M42 screw mount camera. (The East German KW Praktica came out at about the same time.) With earlier “waist level” SLR viewfinder systems (in which the photographer looks downward at the reflex mirror’s image on the focusing screen), moving subjects are seen to track across the field-of-view in reverse direction of their actual motion, making action shooting counter-intuitive. A pentaprism is an eight-sided (only five are of significance; the other three are cut off corners) chunk of glass silvered on three sides that collects, redirects and re-reverses the light from the mirror with minimal light loss. With a proper pentaprism, all a photographer needs to do is hold the camera up to eyelevel and everything is there. The pentaprism SLR had first been proposed in the 19th century and was used in non-35& mm SLRs in the 1930s. Similar systems (or, in the 1990s, its cheaper alternative, the pentamirror) became so common in 35& mm SLRs by the late 1950s that it is the characteristic pentaprism “head” atop the camera body that defines the type for most people.

1950s

;1950: Ihagee Exakta Varex (East Germany; called Exakta V in USA): first interchangeable viewfinder, first interchangeable focusing screens, first viewfinder condenser lens SLR. Original viewfinder selection was waist-level or pentaprism. For the next half-century, interchangeable viewfinder customization was the signal feature of fully professional level SLRs, although they have not made the transition to digital SLRs.

;1950: Angénieux 35mm f/2.5 Retrofocus Type R 1 (France): first retrofocus wide angle lens for 35& mm SLRs (for Exaktas). Regular wide angle lenses (meaning short focal length lenses) need to be mounted close to the film. However, SLRs require that lenses be mounted far enough in front of the film to provide space for the movement of the mirror — the “mirror box.” Therefore, the focal length of early 35& mm SLR lenses were no less than about 40& mm. This prompted the development of wide view lenses with more complex retrofocus optical designs. These use very large negative front elements to force back-focus distances long enough to ensure clearance. Note, “retrofocus” was an Angénieux trademark before losing exclusive status. The original generic term is “inverted telephoto.” A telephoto lens (multiple inventions, 1891) has a front positive group and rear negative group; retrofocus lenses have the negative group in front and positive group to the rear. The first inverted-telephoto imaging lens was the Taylor-Hobson 35mm f/2 (1931, UK) developed to provide back-focus clearance for the beamsplitter prism used by the full-color via three negative Technicolor motion picture process. Retrofocus wide angle prime lenses reached fields of view as wide as 118° with the Nikkor 13mm f/5.6 (Japan) lens for Nikon 35& mm SLRs in 1975, but they are extremely large compared to non-SLR short focal length lenses because of their gigantic negative elements.

;1951: Zenit (Soviet Union, Russia; Зенит): first Russian pentaprism eyelevel viewing 35& mm SLR.

;1952: Asahiflex I (Japan): first Japanese 35& mm SLR. Had folding waist level finder and focal-plane shutter. From 1952 to 1983, Asahi Optical (today called Pentax and owned by Hoya) manufactured cameras exclusively of SLR type and has made them in the greatest variety of formats of any modern camera company – from 110 to 6×7 film, and today’s digital.

;1953: VEB Zeiss Ikon (Dresden) Contax E (East Germany): first built-in light meter SLR. Had an external selenium photoelectric cell mounted behind a door on the pentaprism housing, above the lens. The meter was uncoupled – the photographer would need to wait until the meter stabilized and manually set the shutter speed and lens aperture to match the indicated exposure reading. The first camera with a built-in meter (also uncoupled) was the Zeiss Ikon Contaflex (Germany) 35& mm twin-lens reflex (TLR) camera of 1935.

;1953: Zeiss Ikon Contaflex I (West Germany): first leaf shutter 35& mm SLR. Had Synchro-Compur leaf shutter and fixed 45mm f/2.8 Tessar lens. For many years, reliable focal-plane shutters were very expensive and SLRs equipped with Compur or Prontor leaf shutters were strong competitors. As FP shutters improved, their faster available speeds won out in the late 1960s and leaf shutter 35& mm SLRs disappeared around 1976.

;1953: Metz/Kilfitt Mecaflex (West Germany): first (and only) square format 35& mm SLR. Took up to fifty exposures of 24×24& mm frames on 135 film. A compact Prontor leaf shutter design with bayonet mount interchangeable lenses. 135 film’s standard 24×36& mm frame size is inefficient. Its 3:2 aspect ratio is too wide, recording only 59% of a required 43.3& mm diameter lens image circle. This makes lenses for the format overly large for the image area. A square 24×24& mm frame maximizes coverage at 64% of a smaller 33.9& mm image circle. The Mecaflex’s designer, Heinz Kilfitt, also designed the Robot (Germany) of 1934, the first 24×24& mm 35& mm (not 135 type) camera. Both failed to disturb the entrenched rectangular format and the 3:2 ratio still dominates digital SLRs. Olympus’ Four Thirds System digital format of 2002 is the latest attempt at a narrower, albeit not square, format. Note that dual 24×24& mm frames on 135 film were used by the non-SLR David White Stereo Realist (USA, 1947), leader of the 1950s stereo photography fad.

;1954: Asahiflex IIB (Japan; called Sears Tower 23 in USA): first SLR with reliable instant return mirror.

;1954: Praktina FX (East Germany): first available spring powered motor drive accessory for SLR, first breech-lock lens mount.

;1954: Tokiwa Seiki Firstflex 35 (Japan): first interchangeable lens, leaf shutter 35& mm SLR. Otherwise a wholly forgettable camera; cheaply made to low specifications and of poor quality, with waist level finder.

;1955: Miranda T (Japan): first Japanese pentaprism eyelevel viewing 35& mm SLR. Note that the Tokiwa Seiki Pentaflex (Japan), a modified Firstflex 35 (see above), had an eyelevel viewfinder four months before the Miranda, but using a porroprism. Orion Seiki (company renamed Miranda Camera in 1957) produced a versatile SLR system in the 1960s, called by some “the poor man’s Nikon,” but was unable to keep up with the rapid electronic advancements of the 1970s and went bankrupt in 1977.

;1955: Kilfitt 4& cm f/3.5 Makro-Kilar (West Germany/Liechtenstein): first close focusing “macro” lens for 35& mm SLRs (for Exaktas and others). Version D focused from infinity to 1:1 ratio (life-size) at two inches; version E, to 1:2 ratio (half life-size) at four inches. Because SLRs do not suffer from parallax error, they are far superior for close-up photography than cameras with other viewfinder systems. Most SLR lens lines continue to include macro lenses optimized for high magnification, although their focal lengths tend to be longer than the original Makro-Kilar to allow more working distance. “Macro zoom” lenses began appearing in the 1970s, but traditionalists object to calling most of them macro because they usually do not focus closer than 1:4 ratio with relatively poor image quality.

;1956: Zeiss Ikon Contaflex III (West Germany): first high-quality, interchangeable lens, leaf shutter 35& mm SLR. Was improved Contaflex I (see above) with bayonet mounted front cell lenses.

;1957: Asahi Pentax (Japan; called Sears Tower 26 in USA): first SLR with right-handed rapid-wind thumb lever, first fold-out film rewind crank, first microprism focusing aid. First Asahi SLR with M42 screw mount. Established the “modern” control layout of the 35& mm SLR. Well-integrated focal-plane shutter, instant return mirror and pentaprism design.

;1957: Hasselblad 500C (Sweden): replaced the Hasselblad 1600F/1000F’s (see above) problematic focal-plane shutter with reliable interlens Synchro-Compur leaf shutters and made the 2¼ medium format SLR the dominant professional studio camera by the late 1950s. Well-integrated, durable and reliable design without instant return mirror, but with excellent auto-diaphragm interchangeable lenses and large accessory system.

;1958: Zunow SLR (Japan): first internal auto-diaphragm (Zunow-matic Diaphragm System) 35& mm SLR and lenses. Well-integrated focal-plane shutter, instant return mirror, pentaprism and auto-diaphragm design with excellent lenses and good accessory system. Stopping down (closing) the lens aperture (iris) to prepare for exposure transmits less light to the mirror and the viewfinder may become very dim – perhaps even too dark to see the image. Auto-diaphragms coupled to the shutter release that automatically stop down when the mirror swings up and reopen when the mirror comes down provides almost continuous fully open aperture viewing. Auto-diaphragm lenses and instant return mirror, focal-plane shutter SLRs require precise camera-to-lens linkage, but can choreograph the entire shutter-button release, close lens, raise mirror, open shutter, close shutter, lower mirror, open lens exposure sequence in as little as ⅛th second. Originally, these were mechanical spring/gear/lever systems energized concurrent with manually winding the film, but modern systems are electronically timed and operated by an electromagnet. The financially weak Zunow company was unable to capitalize on its design; few examples of the camera (and much fewer of the wide and tele lenses for it) were produced before the company switched back to lenses for other companies’ cameras. Zunow went bankrupt in 1961. Note, the 1954 version of the Ihagee Exakta VX (East Germany) 35& mm SLR introduced an external auto-diaphragm lens system using a spring-loaded shutter button plunger connection rod.

;1959: Zeiss Ikon Contarex (West Germany): first SLR with a built-in light meter coupled to a viewfinder exposure control indicator – a galvanometer needle pointer. It had an external, circular selenium photoelectric cell mounted above the lens; earning it “Bullseye” (in USA) and “Cyclops” (in UK) nicknames. For proper exposure, the photographer would adjust the meter, which was also coupled to the shutter speed and lens aperture, until the needle was centered on a mark. (The Carl Braun Paxette Reflex [West Germany] leaf shutter SLR had an external top mounted, coupled light meter needle system in 1958.) The Contarex also had interchangeable film backs, a feature common with medium format SLRs and used in a few 35& mm rangefinder cameras, but almost exclusive to Contarex/Contaflex series among 35& mm SLRs. Although Contarex SLRs and their Zeiss lenses were of extremely high quality, they were also extremely expensive and of idiosyncratic (even clumsy) handling.

;1959: Nikon F (Japan): first pro caliber 35& mm system SLR, first electric motor drive accessory for SLR. (The Japanese Nikon SP 35& mm rangefinder camera had the first electric motor drive for any camera type in 1957.) Well-integrated, durable and reliable focal-plane shutter, instant return mirror, pentaprism and auto-diaphragm design with excellent interchangeable lenses and huge accessory system. Although the F was not technologically ground-breaking, it sold 862,600 units and made the 35& mm SLR the dominant professional miniature format camera (displacing the 35& mm RF) by the early 1960s. The perfection of the optical and mechanical formulae of the interchangeable lens SLR in the one-two punch of the Hasselblad 500C (see above) and Nikon F also ended the popularity of the medium format twin-lens reflex (TLR) camera (typified by the Franke & Heidecke Rolleiflex/Rolleicord series [Germany, later West Germany]) by the early 1960s. The F’s improved successor, the Nikon F2 (Japan) of 1971, is widely regarded as the finest mechanically controlled 35& mm SLR camera ever made.

;1959: Voigtländer–Zoomar 1:2.8 f=36mm–82mm (USA/West Germany): first zoom lens for 35& mm still cameras. Designed by Zoomar in USA and manufactured by Kilfitt in West Germany for Voigtländer. Originally mounted for Voigtländer Bessamatic series (West Germany) 35& mm leaf shutter SLRs, but later available in Exakta and other mounts. Zoom lenses and SLR film cameras are perfect for each other, because an SLR always shows what the lens is imaging during zooming, something difficult, if not impossible, to do with other optical viewfinder systems.

1960s

;1960: Konica F (Japan): first SLR with 1/2000 second and 1/125 second flash X-synchronization focal-plane shutter. Modern focal-plane shutters are dual curtain traveling slit shutters. They provide faster shutter speeds by timing the second shutter curtain to close sooner after the first curtain opens and narrowing the slit “wiping” the exposure on the film, instead of moving the curtains faster across film gate, because they are too fragile to survive the necessary accelerative shocks. Long wipe times can cause cartoonish distortion of very fast moving objects instead of truly freezing their motion. (The use of leaning in illustration to give the impression of speed is a caricature of the distortion caused by the slow wiping FP shutters of Graflex large format SLRs from the first half of the 20th century.) Unacceptable distortion (as well as difficulties in precisely timing very narrow slits) had stalled traditional cloth horizontal-travel FP shutters for 35& mm cameras at 1/1000 sec. and 1/60 sec. X-sync for decades. The F’s Copal “High Synchro” Square shutter provided faster speeds by having its metal blades travel vertically along the minor axis of the 24×36& mm frame. In 1982, the Nikon FM2 (Japan) reached 1/4000 sec. (and 1/200 sec. flash X-sync) with a vertical-travel FP shutter using honeycomb pattern etched titanium foil blades, stronger and lighter than plain stainless steel. This allowed quicker shutter-curtain travel time (3.6 milliseconds, about half of earlier vertical, metal bladed shutters) and thereby truly faster shutter speeds. The Nikon FE2 (Japan), with an improved version of this shutter, boosted X-sync speed to 1/250 sec. (3.3 ms curtain travel time) in 1983. The fastest FP shutter ever used in a film camera was the 1/12,000 sec. (1/300 sec. X-sync; 1.8 ms curtain travel time) duralumin and carbon fiber bladed one introduced by the Minolta Maxxum 9xi (Japan) in 1992.

;1960: Royer Savoyflex Automatique (France): first autoexposure SLR. Had an unreliable mechanical shutter-priority autoexposure system controlled by an external selenium light meter, Prontor leaf shutter and fixed 50mm f/2.8 Som-Berthiot lens. The first autoexposure still camera was the non-SLR Kodak Super Kodak Six-20 (USA) of 1938 with a mechanical system controlling both aperture and shutter speed via trapped-needle method coupled to external selenium photoelectric cell.

;1960: Krasnogorsky Mekhanichesky Zavod (KMZ) Narciss (Soviet Union; Нарцисс): first subminiature SLR. Took 14×21& mm frames on unperforated, specially spooled 16& mm film. Compact design with interchangeable lenses and removable finder. Submini film format cameras (those using smaller than 135 film) have always been unpopular with serious photographers because the very high level of enlargement needed to make even small 3½×5& inch prints from such tiny negatives can magnify normally minor image limitations unless using the highest quality cameras, lenses, films and techniques.

;1962: Nikkorex Zoom 35 (Japan): first 35& mm SLR with fixed zoom lens (Zoom-Nikkor Auto 43–86mm f/3.5). Had non-pentaprism, four mirror reflex viewfinder and leaf shutter. Fixed lens SLRs have been an occasional phenomenon bridging simpler viewfinder cameras and more ambitious interchangeable lens SLRs. Presently, they are off-again with non-SLR electronic viewfinder (EVF) superzoom digital cameras occupying this market segment.

;1963: Topcon RE Super (Japan; called Super D in USA; name became Super D worldwide in 1972): first SLR with through-the-lens (TTL) light meter for convenient exposure control. Had internal cadmium sulfide (CdS) photoresistive cells mounted behind non-silvered slits in the reflex mirror for coupled center-the-needle, open aperture, full area averaging metering with auto-diaphragm lenses. Film is rated at a particular “speed” sensitivity. It needs a specific amount of light to form an image. The Weston Universal 617 (USA) helped introduce light exposure metering by a handheld selenium photoelectric device to sense the ambient light in 1932, but miniature light meters built into the camera that gave TTL readings were a great leap forward in convenience introduced by the Feinwerk Technik Mec 16SB (West Germany) non-SLR subminiature (10×14& mm frames on 16& mm film) camera in 1960. TTL metering became normal in virtually all 35& mm SLRs by the late 1960s. The durable and rugged RE Super had excellent interchangeable Exakta mount lenses and was the only pro level 35& mm SLR to compete with the Nikon F (see above) with any success. However, Topcons never progressed and Tokyo Kogaku (or Tokyo Optical) quit the consumer camera business circa 1980.

;1963: Olympus Pen F (Japan): first single frame (also called half frame) 35& mm SLR. Took up to 72 exposures of vertical 18×24& mm frames on 135 film. Had flat-topped non-pentaprism porroprism reflex and optical relay viewfinder, and rotary focal-plane shutter. Well-integrated compact design with excellent interchangeable lenses and large accessory system. The original non-SLR Olympus Pen (Japan) of 1959 helped give 35& mm still cameras that used the standard motion picture frame size of 35& mm film a burst of popularity. It ended by the late 1960s. Although single frame cameras used standard 135 film, single frame photofinishing was always special-order. Kyocera/Yashica unsuccessfully attempted to revive the format as “Double 35″ with their Yashica Samurai series (Japan) SLRs in 1988.

;1964: Asahi (Honeywell in USA) Pentax Spotmatic (Japan): second SLR with coupled center-the-needle TTL metering (stop-down aperture, full area averaging). Well-integrated, compact and reliable focal-plane shutter, instant return mirror and pentaprism design with excellent non-auto-diaphragm interchangeable lenses. Although the Spotmatic’s stop-down (manual diaphragm lenses) system was less convenient than the RE Super’s open aperture (auto-diaphragm lenses) system, the Spotmatic’s two CdS cells on either side of the eyepiece reading off the focusing screen was less expensive and complex than the RE Super’s system (see above), and thereby more popular. The Spotmatic’s TTL system was (and is) very influential and widely imitated, often with open aperture. It (and rival TTL metering SLRs, including the Canon FT [1966; stop-down aperture, partial area], Minolta SRT101 [1966; open aperture, modified centerweighted] and Nikkormat FTN [1967; open aperture, centerweighted]; all from Japan) made the Japanese 35& mm SLR the dominant advanced amateur camera by the late 1960s.

;1964: Krasnogorsky Mekhanichesky Zavod (KMZ) Zenit 5 (Soviet Union; Зенит 5): first SLR with built-in electric motor drive. Had a Ni-Cd battery powered motor for automatic single-frame film advance with a backup film wind knob. In 1970, the Minolta SRM (Japan) was the first SLR with built-in electric sequential motor drive and first SLR with auto film-rewind. It was a modified Minolta SRT101 with a permanently bottom-mounted motor drive (eight AA [LR6] batteries) and detachable handgrip for continuous three frames per second sequence shooting, but no light meter. Built-in motor drives did not become common in 35& mm SLRs until the mid 1980s when high-powered, energy efficient “coreless” micro-motors were perfected, but accessory drives or autowinders taking four to twelve AA (LR6) batteries were very popular in the 1970s. This is, of course, a non-issue in modern digital SLRs.

;1964: Kodak Retina Reflex IV (USA/West Germany): first SLR with standard ISO hot shoe atop the pentaprism housing for direct flash mounting and synchronization. Was a 35& mm, leaf shutter design. A flash is a necessary accessory for auxiliary or fill light in dim or high contrast conditions. The first camera with any kind of hot shoe connector was the Univex Mercury (USA) non-SLR half frame 35& mm in 1938 and many post World War 2 non-SLRs (such as the Bell & Howell Foton [1948, USA] 35& mm rangefinder) had a Leica-type accessory shoe with added electrical contact (the present day ISO hot shoe). Although the Nikon F (see above) had a non-ISO hot shoe surrounding the film rewind crank in 1959, most 1960s 35& mm SLRs used screw-on accessory shoes attached to the eyepiece to mount flashes but a PC cable socket to sync them. The ISO hot shoe became a standard SLR feature feature in the early 1970s. However, in 1971, SLRs using “dedicated” electronic flashes with automatic flash exposure control began appearing with the Canon FTb (Japan). They used ISO-style shoes with extra electrical contacts. Each SLR brand used incompatible contact configurations and the time of use-any-flash-with-any-SLR passed by the late 1970s. Note, although the hot shoe had been ”de facto” standardized in the 1950s, the International Organization for Standardization did not promulgate its ISO 518 hot shoe specification until 1977.

;1965: Canon Pellix (Japan): first pellicle reflex mirror SLR. Virtually all SLRs use fast moving reflex mirrors that swivel out of the way to take the picture, causing mirror shock vibration, blacking-out the viewfinder and delaying shutter firing. Camera shake can blur the image and the subject (which might have moved) cannot be seen at the instant of exposure. A fixed semi-transparent pellicle reflex mirror, reflecting 30% of the light to the viewfinder and transmitting 70% to the film, prevents camera shake and viewfinder blackout, and reduces shutter lag time at the costs of a dimmer viewfinder image, longer exposure times and possible image quality loss. Modern instant return mirrors are fast enough and have efficient enough shock damping systems that the trade offs are not usually considered worthwhile. Pellicle mirror SLRs are very rare and are usually specialized designs for ultra-high speed (10+ frames per second) sequence shooting.

;1966: Praktica Electronic (East Germany) first SLR with an electronically controlled shutter. Used electronic circuitry to time its focal-plane shutter instead of spring /gear/lever clockwork mechanisms.

;1966: Konica Autorex (Japan; called AutoReflex in USA): first 35& mm SLR with successful shutter-priority automation (first with a focal-plane shutter). The camera also had the rare ability to allow selection between frame sizes (horizontal 24×36& mm or vertical 18×24& mm) between frames on the same roll of film. The camera used a mechanical “trap-needle” autoexposure system controlled by an external CdS meter that read light directly (not through-the-lens).

;1967: Zeiss Ikon Contaflex 126 (West Germany): first Kodapak Instamatic 126 cartridge film SLR. Was a Voigtländer focal-plane shutter design unrelated to 35& mm Contaflexes (see above), accepting fully interchangeable lenses. Took up to twenty exposures of 28×28& mm frames on paper-backed, singly-perforated, 35& mm wide film pre-threaded into double-ended cartridge with film supply and take-up spools. Drop-in loading 126 film was introduced in 1963 as Kodak’s first attempt (of many) to solve the problem of amateurs’ difficulty in loading 135 film manually. It was briefly an extremely popular non-SLR snapshot format, but almost dead by 1972.

;1968: Konica Autoreflex T (Japan): first SLR with internal open aperture TTL metering autoexposure (mechanical shutter-priority). Was an improved Konica AutoReflex (see above) with internal CdS centerweighted light meter and reduced shutter button travel, but without half frame capability.

;1968: OP Fisheye-Nikkor 10mm f/5.6 (Japan): first SLR lens with aspherical elements. Was a 180° orthographic projection fisheye lens for Nikon and Nikkormat 35& mm SLRs. Typical lens elements have spherically curved surfaces. However, this causes off-axis light to be focused closer to the lens than axial rays (spherical aberration) and degrading image sharpness; especially severe in very wide angle or aperture lenses. This can be prevented by using elements with convoluted aspheric curves. Although this was understood since the 17th century, the grinding of aspheric glass surfaces was extremely difficult and prevented their consumer use until the E. Leitz 50mm f/1.2 Noctilux (West Germany) in 1966; for Leica M-series 35& mm RFs. The Canon FD 55mm f/1.2 AL (Japan) of 1971 was the first rectilinear aspheric SLR lens; for FD mount Canon SLRs, and the Asahi SMC Takumar 15mm f/3.5 (Japan/West Germany) of 1975 was the first rectilinear aspheric wide angle SLR lens; for M42 screw mount Asahi Pentax SLRs (co-designed with Carl Zeiss [Oberkochen]). The use of modern precision molded plastic or glass aspheric lens elements has made aspheric lenses common today.

;1969: Yashica TL Electro X (Japan): first SLR with all solid-state electronic light metering system. Had a stop-down aperture, full area averaging, CdS light meter linked via a four transistor circuit board to an extinguish-both-red-over-and-underexposure-lights exposure control system instead of a galvanometer meter needle. Also had another four transistor timing circuit to electronically control its metal-bladed Copal Square SE focal-plane shutter.

;1969: Asahi (Honeywell in USA) Pentax 6×7 (Japan; name shortened to Pentax 67 in 1990): first 67 medium format SLR. Took ten exposures of 2¼×2¾ inch (6×7& cm) nominal frames (56×69.5& mm actual frames) on 120 film. The 67 format is called “perfect” or “ideal,” because its aspect ratio enlarges to an 8×10& inch print without cropping. The Pentax 6×7 resembled a greatly scaled-up 35& mm SLR.

1970s

;1970: Mamiya RB 67 (Japan): first 67 medium format system SLR. Took ten exposures of 2¼×2¾ inch (6×7& cm) nominal frames (56×69.5& mm actual frames) on 120 film. Also had “revolving” rotatable interchangeable film backs to easily take vertical photographs with the normally horizontal format and standard interchangeable waist level viewfinder.

;1971: Asahi SMC Takumar lenses (Japan): first all multicoated (Super-Multi-Coated) lenses for consumer cameras; for M42 screw mount Asahi Pentax SLRs. Process co-developed with Carl Zeiss (Oberkochen, West Germany). Lenses with glass elements “single-coated” with a very thin layer (about 130–140 nanometers) of magnesium or calcium fluoride to suppress flare producing surface reflections were invented by Carl Zeiss (Jena, Germany) in 1936 and first sold in 1939. They became standard for high quality cameras by the early 1950s. Coating lenses with up to a dozen different layers of chemicals to suppress reflections across the visual spectrum (instead of at only one compromise wavelength) was a logical progression.

;1971: Asahi Pentax Electro Spotmatic (Japan; name shortened to Asahi Pentax ES in 1972; called Honeywell Pentax ES in USA): first SLR with electronic aperture-priority (using stop-down TTL metering) autoexposure plus electronically controlled shutter. Earlier mechanical AE systems tended to be unreliable, but reliable and convenient AE systems (as well as other electronic control systems) that electronically set either the camera shutter speed or lens aperture from light meter readings once the other was manually set began with the Electro Spotmatic. Rival electronic AE SLRs included the Canon EF (1973; shutter priority), Minolta XE–7 (1975; aperture priority) and Nikkormat EL (1972; aperture priority), all from Japan. Electronic AE came to most 35& mm SLRs by the late 1970s. The Japanese electronic AE SLR effectively ended the German camera industry when they failed to keep up with their Japanese counterparts. After ailing throughout the 1960s, such famous nameplates as Contax, Exakta, Leica, Rollei and Voigtländer went bankrupt, were sold off, contracted production to East Asia, or became boutique brands in the 1970s.

;1971: Praktica LLC (East Germany): first interchangeable lens camera with electric contact lens mount, first camera with electromechanical lens diaphragm stopdown control. Had M42 screw mount modified for open aperture metering. The M42 mount was a very popular interchangeable lens mount system for a quarter century. It was used by almost two dozen different SLR brands, most notably Asahi Pentax. (Asahi became so closely associated with this mount that it was, and still is, often erroneously referred to as the Pentax screw mount.) However, by the early 1970s, the M42′s limitations, especially no provision for auto-diaphragm lens open aperture viewing and metering, were becoming serious liabilities. After unpopular and uncoordinated attempts to modify the screw mount to support auto-diaphragm lenses with open aperture metering, Asahi abandoned the M42 screw mount in 1975, effectively ending production of this lens mounting system.

;1971: Fujica ST701 (Japan): first SLR with silicon photodiode light meter sensors. Early SLR TTL meters used cadmium sulfide (CdS) cells (see Topcon RE Super and Asahi Pentax Spotmatic above), as they were the first sensors small enough to be internally mounted. However, CdS needed fairly bright light and suffered from a “memory” effect where it might take 30 seconds or more to respond to a light level change. Although silicon’s infrared response required blue filtration to match the eye’s spectral response, silicon supplanted CdS by the late 1970s because of its greater sensitivity and instantaneous response.

;1972: Fujica ST801 (Japan): first SLR with viewfinder light emitting diodes. Had a seven LED dot scale to indicate extreme overexposure, +1 EV, +½ EV, 0 (correct exposure), –½ EV, −1 EV, extreme underexposure readings of its silicon photodiode light meter, instead of the traditional but delicate galvanometer needle pointer. A sister camera, the Fujica ST901 (Japan) of 1974, was the first SLR with a viewfinder LED digital data display. It had calculator-style LEDs showing camera’s aperture priority autoexposure set shutter speeds from 20 to 1/1000 second in 14 nonstandard steps. Although they were replaced by more energy efficient and informative LCDs in the 1980s (see Nikon F3, below), the use of LEDs in the ST801/ST901 were major steps in the escalation of electronics in 1970s camera design

;1972: Olympus OM-1 (Japan): first compact full-featured 35& mm SLR. At 83×136×50& mm and 510 g, it was about two-thirds the size and weight of most earlier 35& mm SLRs. Excellent mechanical design with excellent interchangeable lenses and large accessory system. Note that the initial production batches were marked as the M-1, but this designation was quickly changed when E. Leitz objected over conflicts with their Leica M-series RFs trademarks. M-1 marked cameras are currently a collector’s item SLR.

;1972: Polaroid SX-70 (USA): first instant film SLR. Had non-pentaprism mirror reflex system and electronic autoexposure in flat-folding body with bellows and fixed 116mm f/8 lens. Took ten exposure, 3⅛×3⅛ inch frame Polaroid SX-70 instant film packs. The principle of self-developing “instant photography” came to Edwin Land in 1943. The first production instant camera was the non-SLR Polaroid Land Model 95 (USA) of 1948, producing sepia-toned, peel-apart pictures. Steady improvements culminated in the seven year, nearly quarter-billion dollar SX-70 camera and film project to create full-color, self-contained, develop-before-your-eyes, “garbage-free” prints.

;1974: Vivitar Series 1 70–210mm f/3.5 (USA/Japan): first professional-level quality close focusing “macro” zoom lens for 35& mm SLRs. Early zoom lenses often had very inferior optical quality compared to prime lenses, but improvements in computer assisted zoom lens design and construction allowed annual Japanese 35& mm SLR zoom lens production to surpass prime lenses in 1982 and zooms became normal on virtually all but the highest end still cameras by the late 1980s. Ponder & Best’s designed in the USA/made in Japan Vivitar Series 1 lenses were among the best available (many were the first of their kind) for about a dozen years, before new owners debased the brand.

;1975: E. Leitz APO-Telyt-R 180mm f/3.4 (West Germany): first apochromatic lens for consumer cameras (Leicaflex series SLRs). The refractive index of glass increases from red to blue of the light spectrum (color dispersion). Blue is focused closer to the lens than red causing rainbow-like color fringing (chromatic aberration). Most photographic camera lenses are achromatically corrected to bring blue and yellow to a common focus – leaving large residual red and green chromatic aberrations that degrades image sharpness; especially severe in long focus or telephoto lenses. If red, green and blue are brought to a common focus (plus other aberration corrections) with very little residual aberration, the lens is called apochromatic. Chromatic aberration was an issue at the dawn of photography (daguerreotypes [invented 1839] were blue sensitive only, while the human eye focused primarily using yellow), but apochromatic photographic lenses were considered unnecessary until the dominance of color film. The use of extra-low dispersion glasses made most 1980s professional telephotos and many 1990s amateur telephoto zooms apochromatic.

;1975: Mamiya M645 (Japan): first 645 medium format system SLR. Took fifteen exposures of 2¼×1⅝ inch (6×4.5& cm) nominal frames (56×41.5& mm actual frames) on 120 film. Mamiya was never successful at producing 35& mm SLRs, despite a half dozen attempts between 1959 and 1980. However, it was a leader in medium format cameras; first with the Mamiya C series (1956, Japan), the only successful interchangeable lens twin-lens reflex (TLR) cameras ever made, and then with the RB67 (see above) and M645 series SLRs.

;1975: Olympus OM-2 (Japan): first SLR with TTL, off-the-film (OTF) flash autoexposure. Had two rearward facing silicon photodiodes in the mirror box to meter light reflecting off the film. Circuitry could detect when enough light was exposed and automatically quench a specially “dedicated” accessory Olympus Quick Auto 310 electronic flash. Manual flash exposure control for a natural look is complex and convenient TTL autoflash metering became standard in virtually all SLRs by the mid 1980s.

;1976: Canon AE-1 (Japan): first SLR with microprocessor electronics. Well-integrated and compact shutter-priority autoexposure design with excellent interchangeable lenses and large accessory system. Backed by a major advertising campaign, including celebrity endorsements, TV commercials and a catchy slogan (“So advanced, it’s simple.”), that targeted snapshooters, the AE-1 sold five million units and immediately made the 35& mm SLR an important mass-market camera. An improved model, the Canon AE-1 Program (Japan) of 1981, added another four million units to the tally.

;1976: Asahi Pentax ME (Japan): first autoexposure-only SLR. Had aperture-priority exposure control only (photographer could not manually select a shutter speed) for simple snapshooter operation. Interchangeable lens autoexposure-only SLRs disappeared in the mid 1980s, because even snapshooters demanded that SLRs (as “good cameras”) have a manual mode. However, most recent amateurs never use manual control and even some professionals depend on autoexposure, making the great majority of modern SLRs ”de facto” autoexposure-only cameras.

;1976: Minolta 110 Zoom SLR (Japan): first Pocket Instamatic 110 cartridge film SLR. Had built-in zoom lens (fixed 25–50mm f/4.5 Zoom Rokkor-Macro). Took up to 24 exposures of 13×17& mm frames on paper-backed, singly-perforated, 16& mm wide film pre-threaded into double-ended cartridge with film supply and take-up spools. Compact, drop-in loading 110 film was introduced by Kodak in 1972. It was briefly an extremely popular non-SLR snapshot format but almost dead by 1982.

;1977: Fujica AZ-1 (Japan): first interchangeable lens camera to be sold with a zoom lens as the primary lens. The AZ-1′s Fujinon-Z 43-75mm f/3.5-4.5 zoom, despite its modest specifications, was the earliest attempt to supersede the 35& mm SLRs heretofore standard 50 to 58& mm “normal” prime lens with today’s ubiquitous zoom lens. The regular Fujinon-Z 55mm f/1.8 lens remained a popular option. The AZ-1 was also one of the last Japanese-made M42 screw mount cameras released. The purchase of a zoom instead of a prime as the first lens became normal with virtually all amateur 35& mm SLRs in the latter 1980s.

;1977: Minolta XD11 (Japan; called XD7 in Europe, XD in Japan): first dual mode autoexposure SLR. Had both aperture-priority and shutter-priority autoexposure. Previously, each AE SLR brand offered only one or the other mode, and aggressively touted their choice as superior to other. The XD11 offered both modes and trumped the debate.

;1978: Canon A-1 (Japan): first SLR with an electronically controlled programmed autoexposure mode. Instead of the photographer picking a shutter speed to freeze or blur motion and choosing a lens aperture f-stop to control depth of field (focus), the A-1 had a microprocessor computer programmed to automatically select a compromise exposure from light meter input. Virtually all cameras had some sort of program mode or modes by the mid-1980s. It was also the first camera to have all four of the now standard PASM (program/aperture-priority/shutter-priority/manual) exposure modes. Canon’s long term emphasis on the highest possible technology eventually allowed the company to dominate the 35& mm SLR market; first at the amateur level, with their AE-1 (see above) and A-1, and then (despite a stumble in the mid 1980s when they came late to autofocus) the professional level in the early 1990s with the Canon EOS-1 (Japan) of 1989. Canon remains the leading digital SLR maker, with a 38% worldwide market share in 2008.

;1978: Polaroid SX-70 Sonar (USA): first electronic autofocus SLR. Had active ultrasonic sonar echo-location rangefinder AF system. This unique-to-Polaroid AF system had no influence on any other type of AF SLR. Took ten exposure, 3⅛×3⅛ inch frame, Polaroid Time-Zero SX-70 instant film packs.

;1978: Asahi Pentax Auto 110 (Japan): first interchangeable lens Pocket Instamatic 110 film system SLR. Mini-35mm SLR-like programmed autoexposure design with good interchangeable lenses and large accessory system. Was the smallest and lightest SLR ever made – 56×99×45& mm, 185 g with Pentax-110 24mm f/2.8 lens. The Auto 110 and its improved successor, the Pentax Auto 110 Super (Japan) of 1982, were the only interchangeable lens 110 SLRs ever produced and the most advanced 110 cameras ever made, but were unable to prevent the demise of 110 film.

;1979: Konica FS-1 (Japan): first SLR with built-in motorized autoloading. Also had autowinding (motorized single frame or continuous up to 1.5 frames per second film advance), but not auto-rewind. A snapshooter’s great dislike (and Kodak bugbear) of 135 film was the need to manually thread the film leader into the camera’s take-up spool. Built-in, motorized, automated film-transport systems (auto-load/wind/rewind) arrived with the Canon T70 (Japan) in 1984. Completely automated film handling systems appeared when automatic “DX” film speed setting was added to auto-transport in the Minolta Maxxum 7000 (Japan; see below) in 1985 and became standard in virtually all 35& mm SLRs by late 1980s. This is, of course, a non-issue in modern digital SLRs. Although Konishiroku has a rich history including several first rank camera innovations, it was never able to establish Konica as a first tier brand and quit the SLR business in 1988.

;1979: Asahi Pentax ME Super (Japan): first SLR with primarily electronic push button controls. Had increase/decrease push buttons for shutter speed selection instead of a traditional shutter speed dial. As digital computerized SLR features multiplied, push button controls also multiplied and replaced analogue electromechanical dial switches in most 35& mm SLRs by late 1980s.

;1979: Sedic Hanimex Reflex Flash 35 (Australia/Japan): first SLR with built-in electronic flash. Otherwise a wholly forgettable camera; a cheaply made 35& mm SLR of low specifications and poor quality, with a fixed Hanimar 41mm f/2.8 lens and mirror gate shutter.

1980s

;1980: Nikon F3 (Japan): first SLR with viewfinder liquid crystal display digital data display. LCD showed shutter speeds; manual mode and under/overexposure indicators. As computerized SLR features multiplied, comprehensive viewfinder LCD panels became normal in virtually all 35& mm SLRs by late 1980s

;1981: Rolleiflex SL 2000 F (West Germany): first 35& mm SLR to not use the oblong body plus viewfinder head configuration and handling established by the Kine Exacta, 45 years before (see above). Had a cubic body, like a miniature 2¼ medium format SLR, with fixed dual telescopic eyelevel plus folding waist level finder. Also had interchangeable film backs, built-in motor drive, aperture priority AE and TTL autoflash. The 1980s saw varied attempts to stand out in a crowded marketplace by using unconventional 35& mm SLR body layouts. Besides the professional level Rolleiflex, they included the vertical Yashica Samurai series and the flat Ricoh Mirai (both 1988 and from Japan) point-and-shoot SLRs. They were all unsuccessful in establishing a new paradigm and the rectangular body plus pentaprism head layout reemerged universal again in the early 1990s, albeit usually with a large handgrip and rounded contours.

;1981: Pentax ME F (Japan): first built-in autofocus 35& mm SLR. Had passive contrast detection AF system. Autofocused poorly and was not commercially successful. Also had Pentax K-F mount, a unique bayonet lens mount with five electric contact pins to pass focus control information between the ME F and its unique autofocusing SMC Pentax AF 35mm-70mm f/2.8 Zoom Lens. Note that the Ricoh AF Rikenon 50mm f/2 (Japan) lens of 1980 had a self-contained passive electronic rangefinder AF system in a bulky top-mounted box and was the first interchangeable autofocus SLR lens (for any Pentax K mount 35& mm SLR).

;1981: Sigma 21-35mm f/3.5-4 (Japan): first super-wide angle zoom lens for SLRs. For decades, combining the complexities of rectilinear super-wide angle lenses, retrofocus lenses and zoom lenses seemed impossibly difficult. Sigma did the impossible and reached a 91° maximum field of view for 35& mm SLRs with an all-moving eleven element formula through the maturation of computer-aided design and multicoating. In 2004, the Sigma 12-24mm f/4.5-5.6 EX DG Aspherical HSM (Japan) zoom reached 122°, wider than any SLR prime lens ever made, by taking additional advantage of aspherics and low dispersion glasses.

;1982: Ricoh XR-S (Japan): first solar powered SLR. Was a Ricoh XR-7 (Japan) aperture priority AE 35& mm SLR of 1981 modified with two silicon photovoltaic cells in the sides of the pentaprism housing that charged a unique 3 volt 2G13R “5-year” rechargeable silver oxide battery. This battery could be replaced with two regular 1.5 volt S76 (SR44) silver oxide batteries. The XR-7 and XR-S also had unusual viewfinder LCD showing meter pseudo-needle pointing along an analogue shutter speed scale to indicate light meter recommended settings, mimicking a traditional galvanometer needle.

;1982: Polaroid SLR 680 (USA): first high-quality SLR with built-in electronic flash. Also had active sonar echo-location AF system. Took ten exposure, 3⅛×3⅛ inch frame Polaroid 600 instant film packs. Was improved Polaroid SX-70 Sonar (see above) AF SLR with almost-all plastic (acrylonitrile butadiene styrene [ABS]) body, built-in flash and faster film. The SLR 680 represents the zenith of instant photography and was the finest instant camera ever made. For a time in the 1960s and 70s, Polaroid instant cameras outsold all other high-end cameras combined, but the popularity of instant photography waned throughout the 1980s as auto-everything 35& mm point-and-shoot cameras and fast one-hour film developing became common. Polaroid went bankrupt in 2001.

;1983: Pentax Super A (Japan; called Super Program in USA): first SLR with external LCD data display. With push buttons for shutter speed selection instead of a shutter speed dial, the Super Program used an LCD to show set shutter speed. As computerized SLR features multiplied, large external LCD panels became normal on virtually all 35& mm SLRs by the late 1980s.

;1983: Nikon FA (Japan): first camera with multi-segmented (or matrix or evaluative; called Automatic Multi-Pattern) light meter. The FA had a built-in computer system programmed to analyze light levels in five different segments of the field of view for convenient exposure control in difficult lighting situations. After TTL SLR meters were introduced by the Topcon RE Super in 1963 (see above), the various SLR manufacturers tried many different sensitivity schemes (full area averaging, centerweighted, partial area and spot were the most common) in the 1960s before settling in the mid-1970s on centerweighted as the best (90% acceptable exposures) available system. AMP cut the error rate by half. Matrix meters became virtually standard in 35& mm SLRs by 1990 and modern ones are virtually 100% technically accurate. Note however, the technically correct “18% gray” exposure is not necessarily the artistically desirable exposure. In 1996, the number of computer analyzed segments reached a maximum of 1005 in the Nikon F5 (Japan).

;1983: Olympus OM-4 (Japan): first camera with built-in multiple spot-meter (2% of view; 3.3° with 50mm lens). Meter could measure eight individual spots and average them for precise exposure control in difficult lighting situations. Spotmeters versus matrix meters represent the opposite ends of the light meter spectrum: fully manual contemplative metering versus completely computerized instantaneous metering.

;1985: Minolta Alpha 7000 (Japan; called Maxxum 7000 in USA, 7000 AF in Europe): first commercially successful autofocus 35& mm SLR, first passive phase comparison AF SLR, first system AF SLR, first SLR with completely automated film handling (auto-load/wind/rewind/speed setting). Well-integrated PASM autoexposure and built-in motor winder design with very good interchangeable lenses and large accessory system. Ever since the first autofocus camera, the non-SLR Konica C35 AF 35& mm P/S of 1977 (with its built-in passive electronic rangefinder system), AF had been common in 35& mm point-and-shoot cameras. The phenomenal success of the Maxxum temporarily made Minolta the world’s number one SLR brand and permanently made the AF SLR the dominant 35& mm SLR type. Minolta suffered major reverses in the 1990s and was forced to merge with Konica in 2003, and then to transfer its technology to Sony and quit the camera business in 2006, after selling 13.5 million Maxxums.

;1985: Kiron 28-210mm f/4-5.6 (Japan): first very large ratio focal length “superzoom” lens for still cameras. Was first 135 film zoom lens to range from standard wide angle to long telephoto; albeit with a small variable maximum aperture to keep size, weight and cost within reason. Although the 10 to 1 ratio Angénieux 12-120mm f/2.2 (France) zoom had been introduced for 16 mm movie cameras in 1961, and consumer Super-8 movie and Betamax/VHS video cameras long had superzooms, early 35& mm SLR zoom focal length ratios rarely exceeded 3 to 1, because of 135 film’s much higher acceptable image standards. Despite their many image quality compromises, convenient superzooms (sometimes with ratios over 10 to 1) became common on amateur level 35& mm SLRs by the late 1990s. They remain a standard lens on today’s amateur digital SLRs, with the Tamron AF18-270mm f/3.5-6.3 Di II VC LD Aspherical (IF) MACRO attaining 15× in 2008. Note, the Canon DIGISUPER 100 xs, a 100× (9.3-930mm f/1.7-4.7; Japan) broadcast television zoom lens, was introduced in 2002.

;1987: Pentax SFX (Japan; called SF1 in USA): first interchangeable lens SLR with built-in electronic flash (first built-in flash with TTL autoexposure in any camera). Built-in electronic flashes for convenient auxiliary light in dim situations or for fill-light in high contrast situations first appeared on the non-SLR Voigtländer Vitrona (West Germany) of 1964 and had been common on point-and-shoot cameras since the mid 1970s. Built-in TTL autoflashes became standard on all but the most expensive 35& mm SLRs cameras by the early 1990s.

;1987: Canon EF mount (Japan): first all-electronic contact camera lens mount for interchangeable lens cameras. Introduced by Canon EOS 650 and EOS 620 35& mm SLR bodies and Canon EF lenses, this lens mount is essentially a computer data port. Mechanical camera-to-lens linkages can link auto-diaphragm lenses and instant return mirror, focal-plane shutter SLRs, but electronic autofocus required additional electronic data exchange between camera and lens. Canon decided to place everything under electronic control, even though it meant that earlier Canon lenses would not be usable with the new bodies.

;1988: Minolta Maxxum 7000i (Japan; called Dynax 7000i in Europe, Alpha 7700i in Japan): first multi-sensor (three, in an “H” pattern) passive autofocus SLR. First generation AF SLRs had a single central AF sensor. However, composition rules generally say it is wrong to have dead center subjects and most compositions have off-center subjects. Multiple AF sensor arrays covering a wide area can more easily focus on these compositions. In 2007, the number of AF sensors reached 51 in the Nikon D3 and D300 (Japan) digital SLRs. In 1990, the 7000i and a sister camera, the Minolta Maxxum 8000i (Japan, 1990), were also the first 35& mm SLRs with available “panoramic” format film gate mask and focusing screen accessory. Introduced in 1989 by the Kodak Stretch 35 (USA) single-use camera, this 13×36& mm frame on 135 film with 3½×10& inch prints was a faddish snapshot format during the 1990s.

;1989: Yashica Samurai Z-L (Japan): first SLR intentionally designed for left-handed operation. Took up to 72 exposures of horizontal 18×24& mm single frames (also called half frames) on 135 film. Had flat-topped non-pentaprism mirror reflex and optical relay viewfinder. Also had unique-to-Samurai-series vertical body design with fixed autofocus 25–75mm f/4–5.6 zoom lens, interlens leaf shutter, programmed autoexposure, built-in motor drive and electronic flash. Was mirror copy of auto-everything, point-and-shoot Samurai Z camera.

1990s

;1991: Kodak Digital Camera System DCS (USA/Japan): first digital still capture SLR. Was a heavily modified Nikon F3 (Japan) 35& mm SLR and MD-4 motor drive with 1024×1280 pixel (1.3 MP) charge-coupled-device (CCD) sensor, 8 MB DRAM memory and a tethered 200 MB (160 images) Digital Storage Unit (DSU) hard drive. Used manual focus Nikon F mount lenses with 2× lens field of view factor compared to standard 135 film. List price was US$19,995 (standard Nikon F3HP was US$1295 list; MD-4, US$485). Electronic still (then using analogue processing and called still video) photography was first publicly demonstrated by original Sony Mavica (Japan) 490×570 pixel (280 kP) CCD, prototype SLR camera in 1981. The Institute of Electrical and Electronics Engineers has called the DCS’s Kodak KAF-1300 (USA, 1986) image sensor one of “25 Microchips That Shook the World” because the DCS began the digital photography revolution. Digital photography did not alter the basic focal-plane shutter, instant return mirror, pentaprism, auto-diaphragm lens, TTL meter, autoexposure and autofocus formula of SLR camera design developed over the previous century – except, of course, it is filmless.

;1992: Nikonos RS (Japan): first waterproof 35& mm system SLR for 100 m maximum depth, underwater diving use. Had autofocus, autoexposure, TTL autoflash, excellent interchangeable lenses and good accessory system.

;1995: Canon EF 75-300mm f/4-5.6 IS USM (Japan): first SLR lens with built-in image stabilization (called Image Stabilizer; for Canon EOS 35& mm SLRs). Had an electromechanical system to detect and counteract handheld camera/lens unsteadiness, allowing sharp photographs of static subjects at shutter speeds much slower than normally possible without a tripod. The first stabilized lens for consumer cameras was the 38-105mm f/4-7.8 lens built into the Nikon Zoom-Touch 105 VR (Japan) 35& mm point-and-shoot of 1994. Image stabilized lenses were initially very expensive and used mostly by professional photographers. Stabilization surged into the amateur digital SLR market in 2006. However, the Konica Minolta Maxxum 7D (Japan) digital SLR introduced the first camera body-based stabilization system in 2004 and there is now a great engineering and marketing battle over whether the system should be lens-based (counter-shift lens elements) or camera-based (counter-shift image sensor).

;1996: Minolta Vectis S-1 (Japan/Malaysia): first Advanced Photo System (APS) IX240 film SLR. Took up to forty exposures of 16.7×30.2& mm frames on polyethylene napthalate base, singly-perforated 24& mm wide film coated with invisible magnetic data encoding stripe, pre-loaded into self-locking ready-to-use cartridges. Had flat-topped non-pentaprism sideways mirror reflex and optical relay viewfinder. Compact design with good lenses and large accessory system. APS film was introduced by Kodak, Canon, Fuji, Minolta and Nikon in 1996 as Kodak’s last attempt (of many) at drop-in film loading. APS was moderately popular, but faded quickly and almost dead by 2002.

21st century

;2000: Canon EOS D30 (Japan): first complementary metal-oxide-semiconductor (CMOS) sensor digital SLR; first digital SLR intended to be a relatively affordable, advanced amateur level camera. Took up to 1440×2160 pixel (3.11 MP) digital images. Used Canon EF mount lenses with a 1.6× lens factor, compared to 135 film. The use of a cheaper and lower quality CMOS sensor allowed a price (US$3499 initial list price; US$2999 in 2001; body only) about half of contemporary professional CCD digital SLRs; giving ambitious amateurs the choice of an interchangeable lens digital SLR, in addition to the digital point-and-shoots common in the late 1990s.

;2003: Canon EOS Kiss Digital (Japan; called EOS Digital Rebel in USA, EOS 300D Digital in Europe): first sub-US$1000 high-resolution digital SLR. Well-integrated focal-plane shutter, instant return mirror, pentamirror, auto-diaphragm, autoexposure, matrix-metering, autofocus, built-in autoflash, computer-controlled design with excellent lenses and good accessory system. Took up to 2048×3072 pixel (6.3 MP) digital images using a 15.1×22.7& mm complementary metal-oxide-semiconductor (CMOS) sensor (1.6× lens factor). With an original list price of US$899 (body only; US$999 with 18-55mm f/3.5-5.6 Canon EF-S zoom lens), it sold 1.2 million units around the world in sixteen months and was primarily responsible for digital SLR sales vaulting past film SLR sales worldwide in 2004.
Adapted from the Wikipedia article History of the single-lens reflex camera, under the G. N. U. Free Documentation License. Please also see http://en.wikipedia.org/wiki

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The Antonov An-30 is a derivative of the An-24 fitted with an entirely new fuselage forward of frame 11. The fuselage nose is extensively glazed, reminiscent of the Boeing B-29. Housed within the new nose section is the navigator and precise navigational equipment, including an optical sight for ensuring accuracy of aerial photography. To enable accurate and repeatable survey flights, standard equipment for the An-30 included computer flight path control technology. This additional equipment replaced the radar. The positioning of the new navigational equipment required the flightdeck to be raised by 41cm in comparison to the An-24, giving the aircraft its other main feature, a hump containing the cockpit, similar to the Boeing 747.

The radio operator and flight engineer sat in the first cabin aft of and below the flightdeck. The mission equipment was located further aft, in a cabin featuring five camera windows in the floor. Each camera window could be closed with covers to protect the glass panels. The covers were located in special fairings protruding from the fuselage underside. In the normal aerial photography role, four or five cameras were carried aboard. Three cameras were mounted vertically, intended for mapping purposes. The remaining two cameras were pointed at an angle of 28° on each side of the aircraft, for oblique photography. The same fuselage compartment contained workstations for two camera operators and a crew rest area.

The aircraft’s cameras could be used between 2,000 and 7,000 m (6,500 and 23,000 ft) and the scale of the resultant photographs was between 1:200,000 and 1:15,000,000. The aircraft was supplied with four or five cameras.

The An-30 was powered by two Ivchenko AI-24VT turboprops with a take-off rating of 2,820 ehp.

Adapted from the Wikipedia article Antonov An-30, under the G. N. U. Free Documentation License. Please also see http://en.wikipedia.org/wiki

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Punishments for academic dishonesty vary according to the age of the party involved and the nature of the infraction. In high school, a standard penalty for cheating is a failing grade; in college, it can result in expulsion or dismissal (At the University of Virginia for instance, there are no lesser penalties than dismissal for breaches of the honor code). In rare instances, college professors have been fired when it was discovered that they plagiarized during college or graduate school. All parties involved in the dishonesty—not just the individual whose grade is increased by it—can be punished.

Historically the job of preventing cheating has been given to the teacher. It used to be that in college the professor acted ”in loco parentis” and was able to regulate student behavior as a parent. Thus, professors who discovered cheating could assign essentially any punishment they deemed appropriate. This system often had no recourse by which students could appeal judgments. Generally, proctors were hired to patrol exams. If a case was particularly serious, a dean or other top-level administrator might have been involved. Against this inconsistent and paternalistic system, students at some schools rebelled and demanded to be treated as adults.

Honor codes

First at the College of William and Mary in 1779, and then followed by schools like the University of Virginia in the 1850s and Wesleyan University in 1893, the students, with the agreement of faculty who declared themselves dedicated to ideals of democracy and human character, created honor codes. B. Melendez of Harvard University defined an honor code as a code of academic conduct that includes a written pledge of honesty that students sign, a student controlled judiciary that hears alleged violations, unproctored examinations, and an obligation for all students help enforce the code. This system relied on student self-enforcement, which was considered more becoming of young gentlemen than the policing by proctors and professors that existed previously. Of interest, the military academies of the US took the honor code one step further than civilian colleges, disallowing “tolerance”, which means that if a cadet or midshipman is found to have failed to report or outright protected someone engaged in academic dishonesty (as well as other dishonesties or stealing), that individual is to be expelled along with the perpetrator.

Mixed judicial boards

However, many people doubted the advisability of relying on an abstract notion of honor to prevent academic dishonesty. This doubt has perhaps led to the reality that no more than a quarter of American universities have adopted honor codes. Moreover, many professors could not envisage a student run trial process that treated faculty accusers fairly. In response to these concerns, in the middle of the twentieth century, many schools devised mixed judicial panels composed of both students and faculty. This type of academic integrity system was similar to the traditional faculty control system in that it relied on professors to detect cheating, except in this system cheaters were brought before centralized boards of students and faculty for punishment. By the 1960s over a quarter of American universities had adopted this system of mixed judicial boards. Still, though, over half of American universities continued to use faculty-centered control systems.

Student due process rights

Starting in the 1960s the U.S. Supreme Court began chipping away at the ”in loco parentis” doctrine, giving college students more civil liberties such as the right of due process in disciplinary proceedings (”Dixon v. Alabama Board of Education,” 1961). In ”Cooper v. Blair” (1973), specifically academic misconduct was ruled to require due process, being a disciplinary matter and not an educational matter. The due process rights of students in academic misconduct cases is not to the same degree as in a court of law. For instance, the student has no right to representation and the burden of proof is not necessarily stringent. In the “General Order on Judicial Standards of Procedure and Substance in Review of Student Discipline in Tax Supported Institutions of Higher Education”, (1968) student due process rights were laid out as follows:

# The student should be given adequate notice in writing of the specific ground or grounds and the nature of the evidence on which the discipline proceedings are based.

# The student should be given an opportunity for a hearing in which the disciplinary authority provides a fair opportunity for hearing of the student’s position, explanations, or evidence.

# No disciplinary action may be taken on grounds which are not supported by any substantial evidence.

These new rules put an end to the old faculty based system of policing academic dishonesty, now students were entitled to an impartial hearing. While schools using the old honor code method or the mixed judicial system were not affected by these decisions, schools using the faculty based system generally instituted systems that relied on a committee of faculty and administrators or a dean to run the academic misconduct hearings.

Modified honor codes

Recently, Donald L. McCabe and Linda Klebe Trevino, two experts in the field of academic dishonesty, have proposed a new way of deterring cheating that has been implemented in schools such as the University of Maryland. Modified honor codes put students in charge of the judicial hearing process, making it clear that it is the students’ responsibility to stop cheating amongst themselves, but at the same time students still have proctored exams and are not allowed to take pledges of good conduct in place of professor oversight. The researchers who advocate this type of code seem to think that the normal honor code is something of a special case that is not applicable to many schools. According to supporters of this system, schools with a large student body, a weak college community, or no history of student self-governance will not be able to support a full honor code. However, while modified honor codes seem to be more effective than faculty or administration run integrity codes of conduct, research shows that schools with modified codes still have higher rates of cheating than schools with full honor codes.

Comparison of different systems of enforcement

Research has shown that there is a strong correlation between forms of academic integrity system and levels of cheating at a school. Several studies have found students who attend schools with honor codes are less likely to cheat than students at schools with traditional integrity codes. Another study found that only 28% of schools with honor codes have high levels of cheating, whereas 81% of schools with mixed judicial boards have high rates of cheating. Whereas faculty or administration run codes of conduct tend to rely on policing and punishment to deter students from cheating, honor codes tend to rely on and cultivate student senses of honor and group peer pressure to deter academic misconduct. As mentioned above in the section on causes of cheating, increased enforcement or punishment is rarely effective at discouraging cheating, whereas there is a high correlation between peer pressure and academic honesty. The modified honor code attempts to cultivate peer disapproval of cheating while maintaining the traditional proctor system, although critics argue that the proctor system undermines the creation of an atmosphere of student self-policing, reducing the effectiveness of the honor code, possibly explaining why modified honor codes have not been as effective as the original version.

Faculty issues in deterring academic dishonesty

There are limitations to relying on the faculty to police academic dishonesty. One study found that up to 21% of professors have ignored at least one clear cut case of cheating. Another study revealed that 40% of professors “never” report cheating, 54% “seldom” report cheating, and that a mere 6% act on all cases of academic misconduct that confront them. A third survey of professors found that while 79% had observed cheating, only 9% had penalized the student. According to a manual for professors on cheating,

the reasons for this lack of action include unwillingness to devote time and energy to the issue, reluctance to undergo an emotional confrontation, and fear of retaliation by the student, of losing students, of being accused of harassment or discrimination, and even of being sued for these offenses and/or defamation of character.

There are other reasons as well. Some professors are reluctant to report violations to the appropriate authorities because they believe the punishment to be too harsh.

Some professors may have little incentive to reduce cheating in their classes below a point that would otherwise be obvious to outside observers, as they are rated by how many research papers they publish and research grants they win for the college, and not by how well they teach.

Others do not report academic misconduct because of postmodernist views on cheating. Postmodernism calls into question the very concepts of “authorship” and “originality.” From the perspective of cultural studies and historicism, authors themselves are simply constructs of their social surroundings, and thus they simply rewrite already written cultural stories. Moreover, in the field of composition studies, students are being encouraged more and more to do group work and participate in ongoing collective revision. The postmodernist view is that “the concept of intellectual malpractice is of limited epistemological value. Under the ironic gaze of postmodernism, the distinctions between guilt and innocence, integrity and deceit permeating the scandal debates appear irrelevant.” However, there is an argument that postmodernism is just moral relativism, therefore cheating is condoned as a valid academic method, even if it is morally and legally wrong. One professor wrote in an article in ”The English Journal” that when he peeked in on an unproctored class taking a test and saw several students up and consulting with one another, he decided that they were not cheating, but were using non-traditional techniques and collaborative learning to surmount the obstacles teachers had put in their way. Issues of cultural relativism also affect professors’ views on cheating; the standard objection being that “students from certain Middle Eastern, Asian, and African cultures are baffled by the notion that one can ‘own’ ideas, since their cultures regard words and ideas as the property of all rather than as individual property.”

Another issue teachers may have with deterring cheating is that they may decide that it is not their job. The argument that “they’re professors, not policemen” is often heard in academia. In economic terms, some professors believe they are being paid to provide learning, and if the student loses that learning through cheating, he is only cheating himself out of the money he paid.

Adapted from the Wikipedia article Academic dishonesty, under the G. N. U. Free Documentation License. Please also see http://en.wikipedia.org/wiki

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Adapted from the Wikipedia article LCD television, under the G. N. U. Free Documentation License. Please also see http://en.wikipedia.org/wiki

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During 1933, the ”Technisches Amt” (C-Amt), the technical department of the RLM, concluded a series of research projects into the future of air combat. The result of the studies was four broad outlines for future aircraft:

*”Rüstungsflugzeug I” for a multi-seat medium bomber

*”Rüstungsflugzeug II” for a tactical bomber

*”Rüstungsflugzeug III” for a single-seat fighter

*”Rüstungsflugzeug IV” for a two-seat heavy fighter

”Rüstungsflugzeug III” was intended to be a short range interceptor, replacing the Arado Ar 64 and Heinkel He 51 biplanes then in service. In late March 1933 the RLM published the tactical requirements for a single-seat fighter in the document L.A. 1432/33.

The fighter needed to have a top speed of 400& km/h (250& mph) at 6,000& m (19,690& ft), to be maintained for 20 minutes, while having a total flight duration of 90 minutes. The critical altitude of 6,000 metres was to be reached in no more than 17 minutes, and the fighter was to have an operational ceiling of 10,000 metres. Power was to be provided by the new Junkers Jumo 210 engine of about 522& kW (700& hp). It was to be armed with either a single 20& mm MG C/30 cannon firing through the engine shaft or, alternatively, either two engine cowl-mounted 7.92& mm (.312& in) MG 17 machine guns, or one lightweight, engine-mounted 20& mm MG FF cannon with two 7.92& mm MG 17s. The MG C/30 was an airborne adaption of the 2 cm FlaK 30 anti-aircraft gun, which fired very powerful “Long Solothurn” ammunition, but was very heavy and had a low rate of fire. It was also specified that the wing loading should be kept below 100& kg/m2. The performance was to be evaluated based on the fighter’s level speed, rate of climb, and manoeuvrability, in that order.

It has been suggested that Bayerische Flugzeugwerke (BFW) was originally not invited to participate in the competition due to personal animosity between Willy Messerschmitt and RLM director Erhard Milch; however, recent research by Willy Radinger and Walter Shick indicates that this may not have been the case, as all three competing companies—Arado, Heinkel and the BFW—received the development contract for the L.A. 1432/33 requirements at the same time in February 1934. A fourth company, Focke-Wulf, received a copy of the development contract only in September 1939. The powerplant was to be the new Junkers Jumo 210, but the proviso was made that it would be interchangeable with the more powerful, but less developed Daimler-Benz DB 600 powerplant. Each was asked to deliver three prototypes to be delivered for head-to-head testing in late 1934.

Prototypes

Design work on what was to become the Bf 109 began in March 1934, just three weeks after the development contract was awarded, under Messerschmitt Project number P.1034. The basic mock-up was completed by May 1934, and a more detailed design mock-up was prepared by January 1935. The design was issued with the RLM’s designation of “Bf 109″, with the 109 next in line from a batch of type numbers assigned to BFW.

The first prototype (”Versuchsflugzeug 1” or ”V1”), with the civilian registration D-IABI, was completed by May 1935, but the German engines were not yet ready. In order to get the “RIII” designs into the air, the RLM acquired four Rolls-Royce Kestrel VI engines by trading Rolls-Royce a Heinkel He 70 ”Blitz” as an engine test-bed. Messerschmitt received two of these engines and started adapting the engine mounts of V1 to take the V-12 engine upright. This work was completed in August, and V1 completed flight tests in September 1935. The aircraft was then sent to the ”Luftwaffe” test centre at Rechlin to take part in the design contest.

By late-summer, the Jumo engines were starting to become available, and V2 was completed with the 449& kW (600& hp) Jumo 210A in October 1935. V3 followed, being the first to actually mount guns, but another Jumo 210 was not available and it ended up delaying the flight of V3 until May 1936.

The contest

After ”Luftwaffe” acceptance trials were completed at Rechlin, the prototypes were moved to Travemünde for the head-to-head portion of the contest. The aircraft which participated in the trials were the Arado Ar 80 V3, the Focke-Wulf Fw 159 V3, the Heinkel He 112 V4 and the Bf 109 V2. The He 112 arrived first, in early February 1936, and the rest of the prototypes had all arrived by the beginning of March.

Because most of the fighter pilots of the ”Luftwaffe” were used to biplanes with open cockpits, low wing loading, light g-forces and easy handling, they were very critical of the Bf 109 at first. However, it soon became one of the front runners in the contest, as the Arado and Focke-Wulf entries, which were intended as “back-up” programmes to safeguard against failure of the two favourites, proved to be completely outclassed. The Arado Ar 80, with its gull wing (replaced with a straight, tapered wing on the V3) and fixed, spatted undercarriage was overweight and underpowered and the design was abandoned after three prototypes had been built. The parasol winged Fw 159 was always considered by the ”Erprobungsstelle (E-Stelle)” staff at Travemünde to be a compromise between the biplane and the aerodynamically more efficient low-wing monoplane. Although it had some advanced features, it used a novel undercarriage design which was never truly reliable.

Initially, the Bf 109 was regarded with suspicion by the E-Stelle test pilots because of its steep ground angle, resulting in poor forward view on the ground; the sideways-hinged cockpit canopy, which could not be opened in flight; and the automatic wing leading edge slats which, it was thought, would inadvertently open during aerobatics, possibly leading to crashes. They were also concerned about the high wing loading.

The Heinkel He 112, based on a scaled-down ”Blitz” was the favourite of the ”Luftwaffe” leaders. Compared with the Bf 109, it was also cheaper. Positive aspects of the He 112 included the wide track and robustness of the undercarriage, considerably better visibility from the cockpit, and a lower wing loading that led to easier landings. However, the He 112 was also structurally complicated, being some 18% heavier than the Bf 109, and it soon became clear that the thick wing, which spanned 12.6& m (41& ft 4& in) with an area of 23.2& m2 (249.7& ft2) on the first prototype (V1), was a disadvantage for a light fighter, decreasing the aircraft’s rate of roll and manoeuvrability. Because of its smaller, lighter airframe, the Bf 109 was 30& km/h (20& mph) faster than the He 112 in level flight, and superior in climbing and diving. As a result, the He 112 V4 which was used for the trials had new wings, spanning 11.5& m (37& ft 8.75& in) with an area of 21.6& m2 (232.5& ft2). In addition, the V4 had a single-piece, clear-view, sliding cockpit canopy and a more powerful Jumo 210Da engine with a modified exhaust system. However, the improvements had not been fully tested and the He 112 V4 could not be demonstrated in accordance with the rules laid down by the Acceptance Commission, giving a distinct advantage to the Bf 109. The Commission ruled in favour of the Bf 109 because of the Messerschmitt test pilot’s demonstration of the 109′s capabilities during a series of spins, dives, flick rolls and tight turns, throughout which the pilot was in complete control of the aircraft.

In March, the RLM received news that the British Spitfire had been ordered into production; with this information, a quick result to the contest was needed in order to get the winning design into production. On 12 March, they released a document that outlined the results of the contest, ”Bf 109 Priority Procurement”, as a result of which the RLM instructed Heinkel to radically re-design the He 112, while ordering the Bf 109 into production. The Messerschmitt 109 made its public debut during the 1936 Berlin Olympics, when the V1 prototype was flown.

Design features

As with the earlier Bf 108, the new design was based on Messerschmitt’s “lightweight construction”, which was essentially aimed at reducing the total number of parts in the aircraft as much as possible. Examples of this could be found in the use of two large, complicated brackets which were fitted to the main engine firewall; these brackets incorporated the lower engine mounts and landing gear pivot points. A large forging attached to the firewall carried the main-spar pick up points, and carried most of the wing loads. Contemporary design practice was usually to have these main load-bearing structures mounted on different parts of the airframe, with the loads being distributed through the main structure via a series of strong-points. By centralising the loads on the main bulkhead, the main structure of the Bf 109 was able to be made relatively light and uncomplicated.

An advantage of this design was that because the outboard-retracting main landing gear, retracting through roughly an 85º angle, was attached to the fuselage, it was possible to completely remove the wings of the aircraft for servicing without the need for additional equipment to support the fuselage. It also meant that the wing structure was able to be simplified through not having to carry the weight of the aircraft and not having to bear the loads imposed during takeoff or landing. However, this had one major drawback—this landing gear arrangement had a narrow wheel track making the aircraft unstable while on the ground. To increase stability the legs had to be splayed out, creating another problem in that the loads imposed during takeoff and landings were transferred at an angle up through the legs. The small rudder of the Bf 109 was relatively ineffective at controlling the strong swing created by the powerful slipstream of the propeller, and this sideways drift created disproportionate loads on the wheel opposite to the swing. If the forces imposed were large enough, the pivot points often broke and the landing gear leg would be forced sideways into its bay. Because of the large ground angle caused by the long legs, visibility for the pilot, especially straight ahead, was very poor, a problem exacerbated by the sideways-opening canopy. This meant that the pilots often had to “snake” the aircraft during taxiing manoeuvres, which again imposed stresses on the splayed undercarriage legs. Ground accidents were, however, more of a problem with rookie pilots, especially during the later stages of the war. Most Finnish pilots reported that the swing was easy to control, but some of the less-experienced pilots lost fighters on startup. At least 10% of all Bf 109s were lost in takeoff and landing accidents, 1,500 of which occurred between 1939 and 1941. The provision of a fixed “tall” tailwheel on some of the late G-10s and 14s and the K-series helped alleviate the problem to a large extent.

From the inception of the design priority was given to total and easy access to the powerplant, fuselage weapons and other systems while the aircraft was operational from forward airfields. To this end, the entire engine cowling was made up of large, easily removable panels which were secured by large toggle-latches. A large panel under the wing centre-section could be removed to gain access to the L-shaped main fuel tank, which was sited partly under the cockpit floor and partly behind the rear cockpit bulkhead. Other, smaller panels gave easy access to the cooling systems and electrical equipment. The engine was held in two large, forged, magnesium alloy Y-shaped legs which were cantilevered from the main firewall/bulkhead. Each of the legs was secured by two quick-release screw fittings on the main firewall. All of the main pipe connections were colour-coded and grouped in one place, where possible, and the electrical equipment plugged into junction boxes mounted on the firewall. The entire powerplant could be removed or replaced as a unit in a matter of minutes.

An aspect of this construction technique was the use of a single, I-section main spar in the wing, mounted close to the leading edge, thus forming a stiff D-shaped torsion box. Most aircraft of the era used two spars, near the front and rear edges of the wings, but the D-box was much stiffer torsionally, and eliminated the need for the rear spar. The wing profile was somewhere between NACA 2314 and 2315, with a thickness to chord ratio of 14.5%. Another major difference was the higher wing loading than the competing designs. While the R-IV contract called for a wing loading of less than 100& kg/m2, Messerschmitt felt this was unreasonable; with the engines available to them, the fighter would end up slower than the bombers it was tasked with catching.

Since the fighter was being designed primarily for high-speed flight, a smaller wing area would be optimal for achieving high level speeds, but the downside of such a trade-off was that low-speed flight would suffer, as the smaller wing would require more airflow to generate enough lift to stay flying. To compensate for this, the Bf 109 included advanced high-lift devices on the wings, including automatically opening leading edge slats, and fairly large camber-changing flaps on the trailing edge. The slats increased the overall lift of the wing considerably when deployed, greatly improving the horizontal maneuverability of the aircraft, as several Luftwaffe veterans, such as Erwin Leykauf, attest. Messerschmitt also included ailerons (and later radiator flaps) that “drooped” when the flaps were lowered thereby increasing the effective flap area. When deployed, these devices effectively increased the wings’ coefficient of lift.

Fighters with liquid cooled engines were vulnerable to hits to their coolant system. For this reason, on later Bf 109 F, G and K models the two coolant radiators were equipped with a cut-off system: if one radiator leaked, it was possible to fly on the second, or close both radiators down and fly at least five minutes more. In 1943 Oberfeldwebel Edmund Roßmann got lost and landed on the Soviet side, he agreed to show how to service the plane. Machine-gun technician Viktor M. Sinaisky recalled:

Armament and gondola cannons

Reflecting Messerschmitt’s belief in low-weight, low-drag, simple monoplanes, the armament was placed in the fuselage: two synchronized machine guns were mounted in the cowling, firing over the top of the engine and through the propeller arc. As an alternative a single ”Motorkanone” firing through a blast tube between the cylinder banks of the engine was considered from the start. This was also the choice of armament layout on some contemporary French monoplane fighters, such as the Dewoitine D.520. Conforming to Prof. Messerschmitt’s ethos, this kept the gun-free wings very thin and lightweight.

When it was discovered in 1937 that the RAF was planning eight-gun batteries for its new Hawker Hurricane and Supermarine Spitfire fighters, it became clear the Bf 109 would need to carry more weaponry. The problem was that when it came to fitting additional armament, the only place in which it could be located was in the wings. However, the positions of the undercarriage bays, main spar and wing slats meant that room was limited to two bays between the undercarriage and slats. There was room for only one weapon per wing, either a 7.92& mm MG 17 machine gun, or a 20& mm MG FF or MG FF/M cannon.

The first version of the 109 to have wing guns was the C-1, which had one MG 17 per wing fitted in the inner bays. To avoid redesigning the wing to accommodate large ammunition boxes and access hatches, an unusual ammunition feed was devised whereby a continuous belt holding 500 rounds was fed along chutes out to the wing tips. The belt was fed around a roller and back along the wing, forward and beneath the gun breech, to the wing root where it was fed around another roller and back to the weapon. The gun barrels were buried in long, large diameter tubes between the spar and the leading edge. These tubes channelled cooling air around the barrels and breeches and out of a slot at the rear of the wing diaphragm and top of the flap. Room was still so restricted that parts of the MG 17′s breech mechanism poked into an accommodating hole in the flap structure. The much longer and heavier MG FF had to be mounted in the outer bay. A large hole was cut through the spar webbing to allow the cannon to be fitted with an ammunition feed forward of the spar, with the rear breech block projecting through the spar. The 60-round ammunition drum was placed in the machine-gun compartment; a small hatch incorporating a blister was needed in the wing lower surface to allow access to change the drum. The entire weapon could be removed for servicing by removing a leading edge panel.

From the 109F-series onwards, guns were no longer carried ”inside” the wings; a noteworthy exception was Adolf Galland’s field-modified Bf 109 F-2, which had a 20& mm MG FF/M installed internally in each wing.Only some of the projected 109K-series models, such as the K-6, were designed to carry 30& mm (1.18& in) MK 108 cannons in the wings.

In place of internal wing armament, additional firepower was provided through a pair of 20& mm MG 151/20 cannons in conformal gun pods, installed under the wings. Although the additional armament increased the fighter’s potency as a bomber destroyer, it had an adverse affect on the handling qualities, reducing its competence in fighter-versus-fighter combat and accentuating the tendency of the fighter to swing pendulum-fashion in flight. The conformal gun pods, without ammunition, weighed 135& kg (298& lb); and 135 to 145 rounds were provided per gun. The total weight, including ammunition, was 215& kg. Installation of the underwing gun pods was a simple task that could be quickly performed by the unit’s armourers, and imposed a reduction of speed of only 8& km/h (5& mph). By comparison, the installed weight of a similar armament of two 20& mm MG 151/20 cannon inside the wings of the FW 190A-4/U8 was 130& kg (287& lb), without ammunition.

Designation and nicknames

Originally the aircraft was designated as Bf 109 by ”Reichsluftfahrtministerium” (German Aviation Ministry, RLM), since the design was submitted by the ”Bayerische Flugzeugwerke” (literally “Bavarian Aircraft Factory”) company.

However, the company was renamed Messerschmitt AG after 11 July 1938 when Erhard Milch finally allowed Willy Messerschmitt to acquire the company. Subsequently, all Messerschmitt aircraft that ”originated” after that date, such as the Me 210, were to carry the “Me” designation. Despite regulations by the RLM, wartime documents from Messerschmitt AG, RLM and ”Luftwaffe” loss and strength reports continued to use both designations, sometimes even on the same page. All extant airframes are described as “Bf 109″ on identification plates, including the final K-4 models, with the noted exception of aircraft either initially built or re-fitted by Erla Flugzeugwerke, which sometimes bore the Me 109 stamping. “Me-109″ is usually pronounced in German as ”may hundert-neun” (“hundred-nine”) while English-speakers usually say “emm ee one-oh-nine”.

The aircraft was given several nicknames by its operators and opponents, generally derived from the name of the manufacturer (”Messer, Mersu, Messzer” etc.), or the external appearance of the aircraft: the G-6 variant was nicknamed by ”Luftwaffe” personnel as ”Die Beule” (“the bump/bulge”) because of the cowling’s characteristic covers for the breeches of the later Bf 109G’s synchronized 13& mm (.51& in) MG 131 machine guns, while Soviet aviators nicknamed it as “the skinny one” for its sleek appearance (compared to the more robust Fw 190). The names “Anton”, “Berta”, “Caesar”, “Dora”, “Emil”, “Friedrich”, “Gustav” and “Kurfürst” were derived from the variant’s official letter designation (e.g. Bf 109G – “Gustav”), based on the German phonetic alphabet of World War II, a practice that was also used for other German aircraft designs.

Flight records

Soon after the public debut of the new fighter, in July 1937 three Bf 109Bs took part in the Flugmeeting in Zürich. Under the command of Major Seidemann, they won in several categories: First Prize in a 202& km speed race, First prize in the Class A category in the international ”Alpenrundflug” for military aircraft, and also victory in the international ”Patrouillenflug”.

On 11 November 1937 the Bf 109 V13 flown by Messerschmitt’s chief pilot Dr. Hermann Wurster, and powered by an 1650 DB 601R racing engine set a new world air speed record for ”landplanes with piston engines” to 610.55& km/h (379.38& mph) and won the title for Germany for the first time. Converted from a Bf 109D, the “V13″ had been fitted with a special racing DB 601R engine that could deliver for short periods.

Heinkel, having had the He 112 rejected began work on the He 100. On 6 June 1938, the He 100 V3, flown by Ernst Udet, established a new record of 634.7& km/h (394.4& mph), and later, on 30 March 1939, test pilot Hans Dieterle surpassed that record, reaching 746.61& km/h (463.92& mph) with the He 100 V8. Messerschmitt soon regained the lead in this race. On 26 April 1939, ”Flugkapitän” Fritz Wendel, flying the Me 209 V1, raised the figure to 755.14& km/h (469.22& mph). This was a racing aircraft having little in common with the Bf 109, powered by the DB 601ARJ, producing 1,156& kW (1,550& hp) but capable of reaching 1,715& kW (2,300& hp). For propaganda purposes, the machine was called the Bf 109R, suggesting it was just another version of the standard fighter. This world record for a propeller-driven aircraft was to stand until 1969.

Adapted from the Wikipedia article Messerschmitt Bf 109, under the G. N. U. Free Documentation License. Please also see http://en.wikipedia.org/wiki

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From a designer’s point of view, steel plate walls have become a very attractive alternative to other steel systems, or to replace reinforced concrete elevator cores and shear walls. In comparative studies it has been shown that the overall costs of a building can be reduced significantly when considering the following advantages :

* An SPW system, when designed and detailed properly, has relatively large energy dissipation capability with stable hysteretic behaviour, thus being very attractive for high risk earthquake zones.

* Because the web tension field acts much like a diagonal brace, an SPW system has relatively high initial stiffness, and is thus very effective in limiting wind drift.

* Compared to reinforced concrete shear walls, SPWs are much lighter, which ultimately reduces the demand on columns and foundations, and reduces the seismic load, which is proportional to the mass of the structure.

* Compared to reinforced concrete construction, the erection process of an all-steel building is significantly faster, thus reducing the construction duration, which is an important factor affecting the overall cost of a project.

* By using shop-welded, field-bolted SPWs, field inspection is improved and a high level of quality control can be achieved.

* For architects, the increased versatility and space savings because of the smaller cross-section of SPWs, compared to reinforced concrete shear walls, is a distinct benefit, especially in high-rise buildings, where reinforced concrete shear walls in lower floors become very thick and occupy a large proportion of the floor plan.

* All-steel construction with SPWs is a practical and efficient solution for cold regions where concrete construction may not be feasible, as very low temperatures complicate construction and freeze-thaw cycles can result in durability problems.

* In seismic retrofit applications, SPWs are typically much easier and faster to install than reinforced concrete shear walls, which is a critical issue when building occupancy needs to be maintained throughout the construction time.

In comparison with conventional bracing systems, steel panels have the advantage of being a redundant, continuous system exhibiting relatively stable and ductile behaviour under severe cyclic loading (Tromposch and Kulak, 1987). This benefit along with the high stiffness of the plates acting like tension braces to maintain stability, strongly qualifies the SPW as an ideal energy dissipation system in high risk seismic regions, while providing an efficient system to reduce lateral drift. Thus, some of the advantages of using SPWs compared with conventional bracing systems are as follows:

* Reduces seismic force demand due to higher SPW ductility characteristics and inherent redundancy and continuity

* Accelerates structural steel erection by using shop-welded and field-bolted steel panels, and thus, less inspection and reduced quality control costs

* Permits efficient design of lateral-resisting systems by distributing large forces evenly.

A steel plate shear element consists of steel infill plates bounded by a column-beam system. When these infill plates occupy each level within a framed bay of a

structure, they constitute an SPW. Its behaviour is analogous to a vertical plate girder cantilevered from its base. Similar to plate girders, the SPW system optimizes component performance by taking advantage of the post-buckling behaviour of the steel infill panels.

An SPW frame can be idealized as a vertical cantilever plate girder, in which the steel plates act as the web, the columns act as the flanges and the cross beams1 represent the transverse stiffeners. The theory that governs the design of plate girders for buildings proposed by Basler in 1960 , should not be used in design of SPW structures since the relatively high bending strength and stiffness of the beams and columns is expected to have a significant effect in the post-buckling behaviour. However, Basler’s theory could be used as a basis to derive an analytical model for SPW systems.

Designers pioneering the use of SPWs did not have much experience nor existing data to rely upon. Typically, web plate design failed to consider post-buckling behaviour under shear, thus ignoring the advantage of the tension field and its added benefits for drift control and shear resistance. Furthermore, the inelastic deformation capacity of this highly redundant system had not been utilized, also ignoring the significant energy dissipation capability that is of great importance for buildings in high-risk seismic zones. One of the first researchers to investigate the behaviour of SPWs more closely was Kulak at the University of Alberta. Since the early 1980s, his team conducted both analytical and experimental research focused on developing design procedures suitable for drafting design standards (Driver et al., 1997, Thorburn et al., 1983, Timler and Kulak, 1983, and Tromposch and Kulak, 1987). Recent research in the United States by Astaneh (2001) supports the assertion by Canadian academia that unstiffened plate, post-buckling behaviour acts as a capable shear resisting system.

Adapted from the Wikipedia article Steel plate shear wall, under the G. N. U. Free Documentation License. Please also see http://en.wikipedia.org/wiki

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Exterior

When the triptych’s wings are closed, the design of the outer panels becomes visible. Rendered in a green–gray grisaille, the outer panels lack colour, probably because most Netherlandish triptych are thus painted, but possibly indicating that the painting reflects a time before the creation of the sun and moon, which were formed, according to Christian theology, to “give light to the earth”. It was common for the outer panels of Netherlandish altarpieces to be in grisaille, such that their blandness highlighted the splendid colour inside.

The outer panels are generally thought to depict the Creation of the world, showing greenery beginning to clothe the still-pristine Earth. God, wearing a crown similar to a papal tiara (a common convention in Netherlandish painting), is visible as a tiny figure at the upper left. His expression and gestures seem hesitant and morose, according to the art historian Hans Belting, “as though the world he had created was already slipping beyond his control”. Bosch shows God as the father sitting with a Bible on his lap, creating the Earth in a passive manner by divine fiat. Above him is inscribed a quote from Psalm XXXIII reading “Ipse dixit, et facta sunt: ipse mandávit, et creáta sunt”—”For he spake and it was done; he commanded, and it stood fast”. The Earth is encapsulated in a transparent sphere recalling the traditional depiction of the created world as a crystal sphere held by God or Christ. Refracting light, it hangs suspended in the cosmos, which is shown as an impermeable darkness, whose only other inhabitant is God himself.

Despite the presence of vegetation, the earth does not yet contain human or animal life, indicating that the scene represents the events of the biblical Third Day. Bosch renders the plant life in an unusual fashion, using uniformly gray tints which make it difficult to determine whether the subjects are purely vegetable or perhaps include some mineral formations. Surrounding the interior of the globe is the sea, partially illuminated by beams of light shining through clouds. The exterior wings have a clear position within the sequential narrative of the work as a whole. They show an unpopulated earth composed solely of rock and plant, contrasting sharply with the inner central panel which contains a paradise teeming with lustful humanity.

Interior

Scholars have proposed that Bosch used the outer panels to establish a Biblical setting for the inner elements of the work, and the exterior image is generally interpreted as set in an earlier time than those in the interior. As with Bosch’s ”Haywain” triptych, the inner centerpiece is flanked by heavenly and hellish imagery. The scenes depicted in the triptych are thought to follow a chronological order, flowing from left-to-right they represent respectively, Eden, the garden of earthly delights, and Hell. God appears as the creator of humanity in the left hand wing, while the consequences of his will are implied in the right. However, in contrast to Bosch’s two other “true” triptychs, ”The Last Judgment” (after 1482) and ”The Haywain” (completed in 1490), God is absent from the central panel. Instead, this panel shows humanity acting with free will and engaging in various sexual activities. The right hand panel is believed to show God wreaking vengeance for these sins in a Last Judgment hellscape.

Art historian Charles De Tolnay believed that, through the seductive gaze of Adam, the left panel already shows God’s waning influence upon the newly created earth. This view is reinforced by the rendering of God in the outer panels as a tiny figure in comparison to the immensity of the earth. According to Belting, the three inner panels seek to broadly convey the Old Testament notion that, before the Fall, there was no defined boundary between good and evil; humanity in its innocence was unaware of consequence.

Left panel

The left panel (220 × 97.5& cm, 87 × 38.4& in) (sometimes known as the ”Joining of Adam and Eve”) depicts a scene from the paradise of the Garden of Eden commonly interpreted as the moment when God presents Eve to Adam. The painting shows Adam waking from a deep sleep to find God holding Eve by her wrist and giving the sign of his blessing to their union. God is younger-looking than on the outer panels, blue-eyed and with golden curls. His youthful appearance may be a device by the artist to illustrate the concept of Christ as the incarnation of the Word of God. God’s right hand is raised in blessing, while he holds Eve’s wrist with his left, according to the work’s most controversial interpreter, Wilhelm Fränger:

As though enjoying the pulsation of the living blood and as though too he were setting a seal on the eternal and immutable communion between this human blood and his own. This physical contact between the Creator and Eve is repeated even more noticeably in the way Adam’s toes touch the Lord’s foot. Here is the stressing of a rapport: Adam seems indeed to be stretching to his full length in order to make contact with the Creator. And the billowing out of the cloak around the Creator’s heart, from where the garment falls in marked folds and contours to Adam’s feet, also seems to indicate that here a current of divine power flows down, so that this group of three actually forms a closed circuit, a complex of magical energy.

Eve chastely avoids Adam’s gaze, although, according to art historian Walter S. Gibson, she is shown “seductively presenting her body to Adam”. Adam’s expression is one of amazement, and Fränger has identified three elements to his seeming astonishment. Firstly, there is surprise at the presence of the God. Secondly, he is reacting to an awareness that Eve is of same nature as himself, and has been created from his own body. Finally, from the intensity of Adam’s gaze, it can be concluded that he is experiencing sexual arousal and the primal urge to reproduce for the first time.

The surrounding landscape is populated by hut-shaped forms, some of which are made from stone, while others are at least partially organic. Behind Eve, rabbits symbolising fecundity play in the grass, and a dragon tree opposite is thought to represent eternal life. The background reveals several animals that would have been exotic to contemporaneous Europeans, including a giraffe, an elephant and a lion that has killed and about to devour his prey. In the foreground, a circular hole in the ground emits birds and winged animals, some of which are realistic, some fantastic. A fish with human hands and a duck’s head clutches a book while emerging from the cavity in flight, while to the left of the area a cat holds a small creature in its jaws. Belting observes that despite the fact that the creatures in the foreground are fantastical imaginings, many of the animals in the mid and background are drawn from contemporary travel literature, and here Bosch is appealing to “the knowledge of a humanistic and aristocratic readership”. Erhard Reuwich’s pictures for Bernhard von Breydenbach’s ”Pilgrimages to the Holy Land” were long thought to be the source for both the elephant and the giraffe, though more recent research indicates the mid-15th century humanist scholar Cyriac of Ancona’s travelogues served as Bosch’s exposure to these exotic animals.

According to art historian Virginia Tuttle, the scene is “highly unconventional [and] cannot be identified as any of the events from the Book of Genesis traditionally depicted in Western art”. Some of the image’s details seem to contradict the innocence that might be expected in the Garden of Eden before the expulsion. Tuttle and other critics have interpreted the gaze of Adam upon his wife as lustful, and indicative of the Christian belief that man was doomed from the beginning. Gibson believes that Adam’s facial expression betrays not just surprise but also expectation. According to a belief common in the Middle Ages, before the Fall Adam and Eve would have copulated without lust, solely to reproduce. Many believed that the first sin committed after Eve tasted the forbidden fruit was carnal lust. On a tree to the right a snake curls around a tree trunk, while to its right a mouse creeps—both animals are universal phallic symbols. Art historian Rosemarie Schuder, however, suggests that the obvious sensuality of the panel may have been intended as a jab against the Inquisition’s hostility towards physicality.

Centre panel

In the right-hand side of the foreground stand a group of both fair and black-skinned figures. Some of these fair-skinned figures, male and female alike, are covered from head to foot in light-brown body hair. Scholars generally agree that these hirsute figures represent wild or primeval man but disagree on the symbolism of their inclusion. Art historian Patrik Reuterswärd, for example, posits that they may be seen as “the noble savage” who represents “an imagined alternative to our civilized life”, imbuing the panel with “a more clear-cut primitivistic note”. Writer Peter Glum, in contrast, sees the figures as intrinsically connected with whoredom and lust.

In a cave to their lower right a male figure points towards a reclining female who is also covered in hair.(image) The pointing man is the only clothed figure in the panel, and as Fränger observes, “he is clothed with emphatic austerity right up to his throat”. In addition, he is one of the few human figures with dark hair, and the only human who does not have an idealised face; instead his features are remarkably individual. According to Fränger:

The way this man’s dark hair grows, with the sharp dip in the middle of his high forehead, as though concentrating there all the energy of the masculine M, makes his face different from all the others. His coal-black eyes are rigidly focused in a gaze that expresses compelling force. The nose is unusually long and boldly curved. The mouth is wide and sensual, but the lips are firmly shut in a straight line, the corners strongly marked and tightened into final points, and this strengthens the impression—already suggested by the eyes—of a strong controlling will. It is an extraordinarily fascinating face, reminding us of faces of famous men, especially of Machiavelli’s; and indeed the whole aspect of the head suggests something Mediterranean, as though this man had acquired his frank, searching, superior air at Italian academies.

The pointing man has variously been described as either the patron of the work (Fränger in 1947), as an advocate of Adam denouncing Eve (Dirk Bax in 1956), as Saint John the Baptist in his camel’s skin (Isabel Mateo Goméz in 1963), or as a self-portrait. The woman below him lies within a semicylindrical transparent shield, while her mouth is sealed, devices implying that she bears a secret. To their right, a man crowned by leaves lies on top of a gigantic strawberry, and is joined by a male and female who contemplate another large fruit.(image)

There is no perspectival order in the foreground; instead it comprises a series of brief motifs wherein proportion and terrestrial logic are abandoned. Bosch presents the viewer with gigantic ducks playing with tiny humans under the cover of oversized fruit(image); fish walking on land while birds dwell in the water; a passionate couple encased in an amniotic bubble; and a man inside of a red fruit staring at a mouse in a transparent cylinder.

The pools in the fore and background contain bathers of both sexes. In the central lake, the sexes are segregated, and several females adorned by peacocks and fruit stand in a round pond. One woman carries a cherry on her head, a common symbol of pride at the time, as can be deduced from the contemporaneous saying: “Don’t eat cherries with great lords–they’ll throw the pits in your face.” The women are surrounded by a parade of naked men riding horses, donkeys, unicorns, camels, and other exotic or fantastic creatures. One man somersaults on the back of his ride, an act designed to gain the females’ attention that subtly highlights the attraction already felt between the two sexes. The two outer springs also contain both men and women cavorting with abandon. Around them, birds infest the water while winged fish crawl on land. Humans inhabit giant shells. All are surrounded by over-sized fruit pods and eggshells, and both humans and animals feast on strawberries and cherries.

The right panel (220 × 97.5& cm, 87 × 38.4& in) illustrates Hell, the setting of a number of Bosch paintings. Bosch depicts a world in which humans have succumbed to the temptations of the devil and reap eternal damnation. The tone of this final panel strikes a harsh contrast to those preceding it. The scene is set at night, and the natural beauty that adorned the earlier panels is noticeably absent. Compared to the warmth of the center panel, the right wing possesses a chilling quality—rendered through cold colourisation and frozen waterways—and presents a tableau that has shifted from the paradise of the center image to a spectacle of cruel torture and retribution. In a single, densely detailed scene, the viewer is made witness to cities on fire in the background; war, torture chambers, infernal taverns, and demons in the midground; and mutated animals feeding on human flesh in the foreground. The nakedness of the human figures has lost all its eroticism, and many now attempt to cover their genitalia and breasts with their hands.

Large explosions in the background throw light through the city gate and spill forth onto the water in the midground; according to writer Walter S. Gibson, “their fiery reflection turning the water below into blood”. The light illuminates a road filled with fleeing figures, while hordes of tormentors prepare to burn a neighbouring village. A short distance away, a rabbit carries an impaled and bleeding corpse, while a group of victims above are thrown into a burning lantern. The foreground is populated by a variety of distressed, condemned figures. Some are shown vomiting or excreting, others are crucified by harp and lute, in a hallucinatory depiction of the consequences of sin. A choir sings from a score inscribed on a pair of buttocks, part of a group that has been described as the “Musicians’ Hell”.

The focal point of the scene is the “Tree-Man”, whose cavernous torso stands on a pair of rotting tree trunks. His head supports a disk populated by demons and victims together with bagpipes—often used as a dual sexual symbol—reminiscent of human viscera. The tree-man’s torso is formed from a broken eggshell, and is supported by the trunk of a rotten tree whose thorn-like branches pierce his body. A grey figure in a hood bearing an arrow jammed between his buttocks climbs a ladder into the tree-man’s central cavity, where nude men sit in a tavern-like setting. The tree-man gazes outwards beyond the viewer, his conspirative expression a mix of wistfulness and resignation. Belting wondered if the tree-man’s face is a self-portrait, citing the figure’s “expression of irony and the slightly sideways gaze [which would] then constitute the signature of an artist who claimed a bizarre pictorial world for his own personal imagination”.

Below him a gigantic bird-headed monster feeds on the tormented, which he defecates into the transparent chamber pot

on which he sits. The monster is sometimes referred to as the “Prince of Hell”, a name derived from the cauldron he wears on his head, perhaps representing a debased crown.

Many elements in the panel incorporate earlier iconographical conventions depicting hell. However, Bosch is innovative in that he describes hell not as a fantastical space, but as a realistic world containing many elements from day-to-day human life. Animals are shown punishing humans, subjecting them to nightmarish torments that may symbolise the seven deadly sins, matching the torment to the sin. Sitting on an object that may be a toilet or a throne, the panel’s centerpiece is a bird-headed monster feasting on human corpses, which he excretes through a cavity below him. To his left, a group afflicted by a hare-headed demon is being punished for unchastity. Anger is represented by a knight torn down by a pack of wolves to the right of the tree-man. A man lying in his bed is visited by devils punishing sloth, while a proud female gazes at her face reflected on the buttocks of a demon.

During the Middle Ages, sexuality and lust were seen as evidence of man’s fall from grace, and the most foul of the seven deadly sins. This sin is depicted in the left-hand panel through Adam’s gaze towards Eve, and there are many indicators in the center panel to suggest that the panel was created as a warning to the viewer to avoid a life of sinful pleasure. The penalty for such sins is shown in the right panel of the triptych. In the lower right-hand corner, a man is punished for lust as he is beaten by a sow wearing the veil of a nun. The pig is shown forcing the man to sign legal documents. Lust is further symbolised by the gigantic musical instruments and by the choral singers in the left foreground of the panel. Musical instruments often carried erotic connotations in works of art of the period, and lust was referred to in moralising sources as the “music of the flesh”. It may also be that Bosch’s representation here is a rebuke against traveling minstrels, widely thought of as purveyors of bawdy song and verse.

Adapted from the Wikipedia article The Garden of Earthly Delights, under the G. N. U. Free Documentation License. Please also see http://en.wikipedia.org/wiki

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The fourth generation Subaru Outback was introduced in April 2009 at the New York Auto Show, the fifteenth anniversary of the first Outback’s introduction at the same event. The Outback was introduced in Japan May 20, 2009. The “Legacy” prefix has been dropped internationally. Air Bags are offered for the driver and front passenger, side bolster airbags for front seats on the outer edge, side curtain airbags for front and rear passengers and a knee bolster air bag for the driver.

The ground clearance increases to , and is the ninth Subaru vehicle to feature continuously variable transmission (CVT). The double-sized moonroof is no longer being offered, and has been reduced to a conventional size that doesn’t extend over the rear seats. The turbocharged engine is also no longer offered on all international versions of the Outback. An engine coolant temperature gauge is no longer offered, replaced by a fuel economy gauge instead. When the engine temperature is below normal, an indicator light shines blue and when the engine is overheating, the light turns red. Using the key to unlock the drivers door after locking the vehicle with the remote will set off the security system; the vehicle must be unlocked with the remote, a tradition going back to the first generation when remote keyless access was introduced.

The side windows are no longer frameless, ending a Subaru tradition started with the first generation Leone in the early 1970s. The “D” pillar on the wagon is no longer covered in glass, also ending a design tradition established with the first generation and borrowed from the Subaru XT. The front and rear bumper covers are no longer painted a contrasting color, but the plastic side body cladding continues. The external “Limited” badge has been retired on North American vehicles, and if the vehicle has the 3.6 L six cylinder engine, the rear of the vehicle has a “3.6R” badge applied internationally. Black housing for headlights is not offered on the Outback worldwide. January 21, 2010, the Outback was introduced for sale in South Korea.

Subaru introduced improvements to the chassis that they call Dynamic Chassis Control Concept, which uses high-tensile steel in critical areas to achieve high strength with lighter weight. The front-end structure introduces Cradle Mount that isolates the suspension and engine from the passenger compartment for a smoother and quieter ride using rubber mounts. New for this generation is a double wishbone rear suspension, with all suspension links and the rear differential isolated from the rear subframe with large rubber mounts to minimize noise and vibration intruding into the passenger compartment. Subaru has also added safety technologies such as Electronic Stability Control, Brake Assist, and Electronic Brakeforce Distribution to the list of standard features.

In North America, the fifth generation Outback won Motor Trend magazines Sport/Utility of the Year Award for 2010, and Ward’s Automotive Group’s 2010 Interior of the Year awards in the popular-priced car category under $29,999 .

North American models

Trim level designations have been modified based on the engine installed; the Subaru EJ engine 2.5 L naturally aspirated engine are labeled 2.5i, 2.5i Premium, and 2.5i Limited, with the Subaru EZ 6-cylinder engine identified as 3.6R, 3.6R Premium and 3.6R Limited. As with previous generations, leather interior is only available in 2 colors (Warm Ivory or Off-Black) on Limited trim packages on specific exterior colors, and a glass moonroof is optional only on the Limited; cloth interiors are offered in the specified colors on lower trim level packages. A 440 W, 9-speaker Harman/Kardon audio system, using Dolby Pro Logic II technology and DTS Digital Sound, with Bluetooth and iPod capability is optional on the Limited trim packages. An voice activated GPS touch screen navigation system is optional only on the Limited. A separate Bluetooth wireless package with voice recognition, called Blueconnect, is available on lower trim levels and is not offered internationally. A Harmon/Kardon-sourced stereo with a 6-disc in-dash CD changer and SRS Circle Surround sound is the standard sound system offered, with six speakers on all trim levels. A dual zone digital climate control system with 6-speed fan is standard and only available on the Limited; the base and Premium model have a 4-speed fan. Base and Premium trim levels have silver metallic trim on the interior door panels and dashboard; the Limited trim package has woodgrain accents.

All trim levels are fitted with a retractable roof installed luggage rack, where the crossmembers are permanently attached but can be swung into the luggage carrier support structure when not in use, currently available only on North American models. Also, the North American Outback has lower side body claddings, which are not applied to ROW models (although the cladding may come on ROW models as a dealer-installed option). The interior retractable rear cargo cover has a separate storage compartment in the spare tire storage area so that the cargo cover can be removed for large items but stored inside the vehicle and out of the way. The rear seatbacks can be partially reclined for comfort.

All models are now available with painted exterior door handles, with black exterior side mirrors on the base level 2.5i, and painted mirrors on Premium and Limited. The Limited can be identified externally by simulated aluminium surround for the front foglights and matching trim piece on the bottom edges of the side door sill protector, front, and rear bumpers; the Premium and base model remain black. The grille appearance is unique on North American models so as to provide a visual similarity to the larger facelifted Tribeca and the third generation Forester. The 2.5i uses the flat-4 engine with 6-speed manual transmission or the optional Lineartronic Continuously variable transmission with steering column mounted paddle shifters that allows the driver to select 6 “virtual gears” in manual mode. The 3.6R uses the flat-6 engine (from the Subaru Tribeca) exclusively with a 5-speed automatic transmission. The conventional automatic transmission is only available with the flat-6 engine, and the 6-speed manual transmission is not available on the 2.5i Limited. The PZEV Outback 2.5i, identified by a badge attached to the rear of the vehicle, continues to be sold in all 50 states, unlike other manufacturers who only sell PZEV certified vehicles in states that have adopted California emission standards. All other models have been certified LEV2 or ULEV.

Japanese models

The Japanese-specification Outback is available with either the 2.5 L flat-4 or the 3.6 L flat-6 engine. The EJ20 engine is no longer used in the Legacy or the Legacy Outback. The trim levels are 2.5i, 2.5i L package and 3.6R and 3.6R SI-Cruise. ”SI-Cruise” is an autonomous cruise control system that can reduce or resume a preset speed or bring the vehicle to a complete stop if the system detects a slower vehicle is being followed, without driver intervention. Air vents are installed for rear passengers at the back of the center front armrest compartment. The front hood (bonnet) and front bumper covers are not interchangeable with the North American version due to slight changes in the sheet metal.

Turn signal repeaters are still integrated into the side exterior mirrors on all Japanese-spec models. Woodgrain accents are standard on the “L” package and the SI-Cruise vehicle, silver accents on lower trim levels.

SI-Drive, or Subaru Intelligent-Drive [http://www.subaru.jp/technology/index.html], is standard equipment on all trim versions. It is a feature that enables three distinctly different modes of vehicle performance characteristics (identified as “Sport”, “Sport Sharp”, and “Intelligent”) by regulating the engine control unit (ECU), the automatic transmission control unit (TCU, if equipped), and by fine-tuning the electronically controlled throttle. The SI-Drive control knob is installed on the center console between the heated front seat control switches. The “Intelligent” mode makes throttle response more gradual, and decreases maximum engine power by 10 percent. The “Sport” mode allows the engine to run at higher speeds and increases fuel efficiency by 5 percent in comparison to Subaru engines without the feature. The “Sport # (Sharp)” mode makes throttle response more abrupt and enables the automatic transmission to maintain higher RPMs within a given gear’s range, and minimizes the electric power steering wheel effort. When the engine is started, the default setting is the “Sport” selection.

Japanese buyers can choose two different premium level entertainment systems; they can select the previously described Harmon/Kardon GPS-stereo with six speakers, or a McIntosh sourced GPS/stereo with Dolby Digital 5.1 Surround Sound, a separate powered amplifier and 10 speakers. Both units are Gracenote, G-BOOK and VICS enabeled, with both systems available with an internal 600& MHz 40GB HDD coupled with a digital TV tuner that can be watched when the transmission is in park and the parking brake applied. Both stereos are compatible with CD, CD-R/RW, DVD and DVD R/RW as well as MP3 and WMA music formats. A Harmon/Kardon sourced stereo with a 6-disc in-dash CD changer and SRS Circle Surround sound is the entry level sound system offered with six speakers and is standard equipment. The McIntosh stereo facia is offered in the trademark black with a clear plastic overlay and the center dashboard trim piece retains the brushed aluminum appearance but the color is black, with the climate controls offered in a matching black appearance, instead of the standard silver. Oddly, the Japanese version has a retractable cover for the console installed cupholders, whereas the North American version has exposed cupholders without a retractable cover. The dual-zone climate control system is standard on all trim levels.

The GPS navigation system can be displayed in a split-screen format showing both two- and three dimensions with graphic landmarks instead of a flat screen without geographical images. HID headlights are standard on all models except the base 2.5i, as well as automatic rain sensing windshield wipers and headlight washers. A smart key is available as an option coupled with two position memory seat that memorizes driver’s seat positions and adjustments, exterior mirror adjustment, and climate control settings. The settings can be customized based on the smart key module being used to unlock and start the car. The Outback can be fitted with twin white LED lights installed on the interior hatch vertically surrounding the rear window, with a separate light switch for additional illumination when the rear hatch is open.

On the one year anniversary of the introduction of the fourth generation, “EyeSight” was once again offered on the Japanese-spec Outback. EyeSight consists of 2 cameras with one on each side of the interior rear view mirror, that use human like stereoscopic vision to judge distances and generally keep tabs on the driver. The system can help maintain a safe distance on the highway, a lane departure warning system, a wake up call when traffic lights change, and even keeps an eye out for pedestrians. SI-Cruise has been integrated into the EyeSight feature as a driver safety aid.

European models

The European engine choices are the flat-4 EE20 2.0 L turbodiesel, the EJ25 2.5 L or the EZ36 3.6 L flat-6, with SI-Drive available only on the six cylinder. Trim level packages are the 2.0D Comfort, Trend and Active, the 2.5i Comfort and Trend, or the 3.6R Exclusive. The interior colors of Warm Ivory or Off Black are offered, but the Warm Ivory interior is only available in leather. Wood accents are only available on the Exclusive trim package. The dual-zone climate control system is standard on all trim levels. The turbodiesel is available with the Warm Ivory interior with the Harmon/Kardon sound system with six speakers and the satellite navigation, but the only transmission offered is the six speed manual transmission. Cruise control, heated seats, automatic windshield wipers, HID headlights with headlight washers, heated exterior mirrors, glass moonroof and 17″ wheels are standard equipment. The smart key is available only on the Exclusive or Comfort trim packages, coupled with the satellite navigation system and memory seats. The front hood (bonnet) and front bumper covers use the Japanese configuration, with turnsignal repeaters on the exterior mirrors, and standard equipment front and rear foglights. The turbodiesel and the 2.5i engines are Euro5 compliant.

United Kingdom models

The Outback is available to United Kingdom buyers with a choice of the flat-4 Subaru EE turbodiesel with a 6 speed manual transmission, the 2.5 L flat-4 with the CVT transmission, or the 3.6 L flat-6 engine with SI-Drive and an 5-speed automatic transmission. The trim level packages are the 2.0D SE and 2.0D SE NavPlus diesel, the 2.5i SE and the 2.5i SE NavPlus and the 3.6R. The interior is offered in black only, with leather on all trim levels. The interior trim strips on the doors and dashboard are silver on all models except the 3.6R, which has woodgrain trim. The front bumper and bonnet use the Japanese configuration, to include self levelling HID headlights and headlight washers. The UK and Europe are offered a exterior paint selection, called Camellia Red Pearl that is not available in Japan or North America. For vehicle security, a Thatcham Category 1 perimeter alarm and immobiliser, along with a rolling code ECU engine immobiliser are standard equipment. The dual-zone climate control system is standard on all trim levels. The 2.5i and the turbodiesel engines are Euro5 compliant.

The smart key is available on NavPlus and 3.6R models only. 17″ alloy wheels are standard on all models, as well as rain sensing automatic wipers, two position memory seat, heated exterior mirrors, glass moonroof, heated front seats, fog lights, and tilt and telescoping steering wheel. The Harman/Kardon stereo with 6 speakers and the rear view backup camera is installed only on vehicles with the voice recognition NavPlus system. The standard stereo system uses an in-dash 6-disc CD auto-changer and automatic speed-sensing volume adjustment that is MP3 player compatible.

South African models

[http://www.subaru.co.za/sitefiles/8E9250DD-E877-4F0F-A248-0AA1A67D4CD5/gallery/10_28_20093_06_02_PMOutback_Brochure.pdf]

The Outback is offered with black interior; specifications are similar to European “Comfort” trim package. Outback 2.5i Premium is available with the choice of Lineartronic CVT or six-speed manual transmission, including leather trim, memory function for the driver’s seat, electric sunroof, dual zone climate control and rear air vents. Satellite navigation is not offered along with the premium Harmon/Kardon sound system.

Australian models

The Outback sold in Australia resembles the vehicle sold in Europe, with some features only available in Japan. The trim level packages are the 2.5i, 2.5i Premium, 2.5i Premium SatNav, the 3.6R, 3.6R Premium SatNav and the diesel 2.0D, 2.0D Premium, 2.0D Premium SatNav. The engines offered are the EJ25, EZ36 and the EE20 turbodiesel. Australians can choose either the Lineartronic CVT or a 6-speed manual transmission on the EJ25, but transmission choices on the EZ36 are limited to the 5-speed automatic, and the EE20 turbodiesel is available with the 6-speed manual transmission exclusively. The Off Black interior color is standard across the range, however the Warm Ivory is available on the 3.6R, with leather interior offered on vehicles identified as “Premium”. Cloth is offered on the 2.5i, 3.6R and the 2.0D. SI-Drive is only available on the 3.6R, following the international trend. The front bumper and hood (bonnet) use the Japanese configuration. The Australian EJ25 and EE20 engines are Euro4 compliant.

The dual-zone climate control system is standard on all trim levels. Sound systems offered include the McIntosh stereo with 10 speakers, a separate powered amplifier and satellite navigation provided by “[http://www.whereis.com/ WhereIs]“, a service provided by Telstra Corporation Ltd, or the Harmon-Kardon stereo with the satellite navigation and 6 speakers, or the unit offered in North America and Europe with a 6-disc in-dash CD changer and 6 speakers. The McIntosh unit sold in Australia has function buttons written in English and is different than the Japanese unit, due to Japanese characters being used on some of the functions. The Australian McIntosh or Harmon/Kardon GPS-stereo packages are not Gracenote, G-BOOK and VICS enabled, and do not have the internal 600& MHz 40GB HDD coupled with a digital TV tuner. The center dashboard trim is color matched based on the stereo installed; if it has either one of the Harmon-Kardon units, the trim color is silver brushed aluminum, and if the McIntosh is installed the trim color is black brushed aluminum. The climate controls are also colored either silver or black as well. Silver trim is installed on the doors and dashboard, with woodgrain available only on the 3.6R. Cruise control, heated seats, automatic windshield wipers, HID headlights with headlight washers, heated exterior mirrors, and 17″ wheels are standard equipment. The smart key is available only on the 3.6R, and the glass moonroof is only offered on Premium trim packages.

Engines

Transmissions

Adapted from the Wikipedia article Subaru Outback, under the G. N. U. Free Documentation License. Please also see http://en.wikipedia.org/wiki

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