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A single-lens reflex camera (SLR) is a
camera A camera is an Optics, optical instrument that can capture an image. Most cameras can capture 2D images, with some more advanced models being able to capture 3D images. At a basic level, most cameras consist of sealed boxes (the camera body), ...
that typically uses a mirror and prism system (hence "reflex" from the mirror's reflection) that permits the photographer to view through the lens and see exactly what will be captured. With
twin lens reflex A twin-lens reflex camera (TLR) is a type of camera with two objective lenses of the same focal length. One of the lenses is the photographic objective or "taking lens" (the lens that takes the picture), while the other is used for the viewfind ...
and
rangefinder cameras A rangefinder camera is a camera fitted with a rangefinder, typically a split-image rangefinder: a range-finding focusing mechanism allowing the photographer to measure the subject distance and take photographs that are in sharp focus. Most var ...
, the viewed image could be significantly different from the final image. When the shutter button is pressed on most SLRs, the mirror flips out of the light path, allowing light to pass through to the light receptor and the image to be captured.


History

File:Hasselblad 1600F.jpg,
Medium format Medium format has traditionally referred to a film format in photography and the related cameras and equipment that use film. Nowadays, the term applies to film and digital cameras that record images on media larger than the used in 35&nbs ...
SLR by
Hasselblad Victor Hasselblad AB is a Swedish manufacturer of medium format cameras, photographic equipment and image scanners based in Gothenburg, Sweden. The company originally became known for its classic analog medium-format cameras that used a waist ...
(Model 1600F), Sweden File:Zenza BRONICA S2 with ZENZANON 100mm F2.8.JPG, Medium format SLR by
Bronica Bronica also Zenza Bronica (in Japanese: ) was a Japanese manufacturer of classic medium-format roll film cameras and photographic equipment based in Tokyo, Japan. Their single-lens reflex (SLR) system-cameras competed with Pentax, Hasselblad, Ma ...
(Model S2), Japan. Bronica's later model—the Bronica EC—was the first medium format SLR camera to use an electrically operated
focal-plane shutter In camera design, a focal-plane shutter (FPS) is a type of photographic shutter that is positioned immediately in front of the focal plane of the camera, that is, right in front of the photographic film or image sensor. Two-curtain shutters ...
File:Asahiflex600.jpg, The 1952 (
Pentax is a brand name used primarily by the Japanese multinational imaging and electronics company Ricoh for DSLR cameras, lenses, sport optics (including binoculars and rifle scopes), and CCTV optics. The Pentax brand is also used by Hoya Corporatio ...
)
Asahiflex The Asahiflex was a 35 mm single-lens reflex camera built by the Asahi Optical Corporation (later to become Pentax). It was regarded as the first SLR camera built in Japan. Asahi Optical introduced its first 35 mm camera in 1952. Unlike t ...
, Japan's first single-lens reflex camera. File:Contaflex BW 2.JPG, The
Contaflex The Contaflex series is a family of 35mm leaf-shuttered SLR cameras, produced by Zeiss Ikon in the 1950s and 1960s. The name was first used in 1935 on a 35mm Twin-lens reflex camera, the ''Contaflex TLR'' also by Zeiss Ikon, the -flex part in th ...
III a single-lens reflex camera from West Germany from 1957, with additional 115 mm lens File:Nikonf.jpg, The 35 mm film-based
Nikon F The Nikon F camera, introduced in April 1959, was Nikon's first SLR camera. It was one of the most advanced cameras of its day. Although many of the concepts had already been introduced elsewhere, it was revolutionary in that it was the firs ...
, 1959, the world's second single-lens reflex
system camera A system camera or camera body is a camera with interchangeable components that constitutes the core of a system. Early representatives include Leica I Schraubgewinde (1930), Exakta (1936) and the Nikon F (1959). System cameras are often sin ...
. The first was Kamera-Werke's Praktina. File:Canon pellix.jpg,
Canon Pellix The Canon Pellix is a manual-focus single-lens reflex (SLR) camera released in 1965 that uses a stationary half-silvered mirror behind which a metering cell is raised during light level metering. The First Canon with TTL Canon suddenly switche ...
, 1965, the first camera to incorporate a stationary pellicle mirror. File:Honeywell-Pentax-Spotmatic.jpg, The
Pentax is a brand name used primarily by the Japanese multinational imaging and electronics company Ricoh for DSLR cameras, lenses, sport optics (including binoculars and rifle scopes), and CCTV optics. The Pentax brand is also used by Hoya Corporatio ...
Spotmatic IIa, 1971 File:OM-2-2.jpg, Olympus The 35 mm film-based
Olympus OM-2 The Olympus OM-2 is a single-lens reflex film system camera produced by Olympus of Japan. Main features The Olympus OM-2 is an aperture-priority automatic-exposure camera (with full manual operation selected via switch), based on the earlier, s ...
(1975), which was the first SLR to measure light for electronic flash off the film plane. File:Casio RF2.JPG,
Casio is a Japanese multinational electronics manufacturing corporation headquartered in Shibuya, Tokyo, Japan. Its products include calculators, mobile phones, digital cameras, electronic musical instruments, and analogue and digital watches. I ...
RF2 35 mm film SLR File:16-04-09 Nikon F5 RalfR WAT 6948.jpg,
Nikon F5 The Nikon F5 is a 35 mm film-based single-lens reflex camera body manufactured by Nikon from 1996 through 2004. It was the fifth in Nikon's professional film camera line, which began in 1959 with the Nikon F. It followed the Nikon F4 of 1988, w ...
professional SLR, 1996 File:Coolscan-V.jpg,
Digital SLR A digital single-lens reflex camera (digital SLR or DSLR) is a digital camera that combines the optics and the mechanisms of a single-lens reflex camera with a digital imaging sensor. The reflex design scheme is the primary difference between ...
Nikon D200 and a Nikon
film scanner A film scanner is a device made for scanning photographic film directly into a computer without the use of any intermediate printmaking. It provides several benefits over using a flatbed scanner to scan in a print of any size: the photographe ...
File:Image of Russian-made Zennit without lens kit.jpg, Zenit, a Russian brand. SLR without lens kit
Prior to the development of SLR, all cameras with viewfinders had two optical light paths: one path through the lens to the film, and another path positioned above ( TLR or ''twin-lens reflex'') or to the side (
rangefinder A rangefinder (also rangefinding telemeter, depending on the context) is a device used to measure distances to remote objects. Originally optical devices used in surveying, they soon found applications in other fields, such as photography an ...
). Because the viewfinder and the film lens cannot share the same optical path, the viewing lens is aimed to intersect with the film lens at a fixed point somewhere in front of the camera. This is not problematic for pictures taken at a middle or longer distance, but
parallax Parallax is a displacement or difference in the apparent position of an object viewed along two different lines of sight and is measured by the angle or semi-angle of inclination between those two lines. Due to foreshortening, nearby objects ...
causes framing errors in close-up shots. Moreover, focusing the lens of a fast reflex camera when it is opened to wider
aperture In optics, an aperture is a hole or an opening through which light travels. More specifically, the aperture and focal length of an optical system determine the cone angle of a bundle of rays that come to a focus in the image plane. An opt ...
s (such as in low light or while using low-speed film) is not easy. Most SLR cameras permit upright and laterally correct viewing through use of a roof pentaprism situated in the optical path between the reflex mirror and viewfinder. Light, which comes both horizontally and vertically inverted after passing through the lens, is reflected upwards by the reflex mirror, into the pentaprism where it is reflected several times to correct the inversions caused by the lens, and align the image with the
viewfinder In photography, a viewfinder is what the photographer looks through to compose, and, in many cases, to focus the picture. Most viewfinders are separate, and suffer parallax, while the single-lens reflex camera lets the viewfinder use the main ...
. When the shutter is released, the mirror moves out of the light path, and the light shines directly onto the film (or in the case of a
DSLR A digital single-lens reflex camera (digital SLR or DSLR) is a digital camera that combines the optics and the mechanisms of a single-lens reflex camera with a digital imaging sensor. The reflex design scheme is the primary difference between a ...
, the CCD or CMOS imaging sensor). The Canon Pellix, along with several special purpose high speed cameras(such as the Canon EOS-1N RS), were an exception to the moving mirror system, wherein the mirror was a fixed beamsplitting pellicle. Focus can be adjusted manually by the photographer or automatically by an
autofocus An autofocus (or AF) optical system uses a sensor, a control system and a motor to focus on an automatically or manually selected point or area. An electronic rangefinder has a display instead of the motor; the adjustment of the optical system ...
system. The viewfinder can include a matte focusing screen located just above the mirror system to diffuse the light. This permits accurate viewing, composing and focusing, especially useful with interchangeable lenses. Up until the 1990s, SLR was the most advanced photographic preview system available, but the recent development and refinement of digital imaging technology with an on-camera live LCD preview screen has overshadowed SLR's popularity. Nearly all inexpensive compact digital cameras now include an LCD preview screen allowing the photographer to see what the CCD is capturing. However, SLR is still popular in high-end and professional cameras because they are
system camera A system camera or camera body is a camera with interchangeable components that constitutes the core of a system. Early representatives include Leica I Schraubgewinde (1930), Exakta (1936) and the Nikon F (1959). System cameras are often sin ...
s with interchangeable parts, allowing customization. They also have far less
shutter lag In photography, shutter lag is the delay between triggering the shutter and when the photograph is actually recorded. This is a common problem in the photography of fast-moving objects or animals and people in motion. The term narrowly refers only ...
, allowing photographs to be timed more precisely. Also the
pixel In digital imaging, a pixel (abbreviated px), pel, or picture element is the smallest addressable element in a raster image, or the smallest point in an all points addressable display device. In most digital display devices, pixels are the smal ...
resolution,
contrast ratio The contrast ratio (CR) is a property of a display system, defined as the ratio of the luminance of the brightest shade (white) to that of the darkest shade (black) that the system is capable of producing. A high contrast ratio is a desired aspec ...
,
refresh rate The refresh rate (or "vertical refresh rate", "vertical scan rate", terminology originating with the cathode ray tubes) is the number of times per second that a raster-based display device displays a new image. This is independent from frame rate ...
, and color
gamut In color reproduction, including computer graphics and photography, the gamut, or color gamut , is a certain ''complete subset'' of colors. The most common usage refers to the subset of colors which can be accurately represented in a given circ ...
of an LCD preview screen cannot compete with the clarity and shadow detail of a direct-viewed optical SLR viewfinder.
Large format Large format refers to any imaging format of or larger. Large format is larger than "medium format", the or size of Hasselblad, Mamiya, Rollei, Kowa, and Pentax cameras (using 120- and 220-roll film), and much larger than the frame ...
SLR cameras were probably first marketed with the introduction of C.R. Smith's ''Monocular Duplex'' (U.S., 1884). SLRs for smaller exposure formats were launched in the 1920s by several camera makers. The first 35 mm SLR available to the mass market, Leica's PLOOT reflex housing along with a 200 mm f4.5 lens paired to a 35 mm rangefinder camera body, debuted in 1935. The Soviet ''Спорт'' (“Sport”), also a 24 mm by 36 mm image size, was prototyped in 1934 and went to market in 1937. K. Nüchterlein's
Kine Exakta The Kine Exakta was the first 35mm single-lens reflex (SLR) still camera in regular production. It was presented by Ihagee Kamerawerk Steenbergen GmbH, Dresden at the Leipziger Frühjahrsmesse in March 1936. The Exakta name had already been use ...
(Germany, 1936) was the first integrated 35 mm SLR to enter the market. Additional
Exakta The Exakta (sometimes Exacta) was a camera produced by the ''Ihagee Kamerawerk'' in Dresden, Germany, founded as the Industrie und Handels-Gesellschaft mbH, in 1912. The inspiration and design of both the VP Exakta and the Kine Exakta are the wo ...
models, all with waist-level finders, were produced up to and during
World War II World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposin ...
. Another ancestor of the modern SLR camera was the Swiss-made
Alpa Alpa was formerly a Switzerland, Swiss camera design company and manufacturer of 135 film, 35 mm Single-lens reflex camera, SLR cameras. The current owners bought the company name after bankruptcy of the original company and the company exists ...
, which was innovative, and influenced the later Japanese cameras. The first eye-level SLR viewfinder was patented in Hungary on August 23, 1943, by Jenő Dulovits, who then designed the first 35 mm camera with one, the Duflex, which used a system of mirrors to provide a laterally correct, upright image in the eye-level viewfinder. The Duflex, which went into serial production in 1948, was also the world's first SLR with an instant-return (a.k.a. autoreturn) mirror. The first commercially produced SLR that employed a roof
pentaprism A pentaprism is a five-sided reflecting prism used to deviate a beam of light by a constant 90°, even if the entry beam is not at 90° to the prism. The beam reflects inside the prism ''twice'', allowing the transmission of an image through a r ...
was the Italian
Rectaflex Rectaflex was the world's first series produced Pentaprism single lens reflex camera. It was produced from 1948 to 1958. Rectaflex was the only Italian single-lens reflex camera ever built. There has been some uncertainty about the Rectaflex being ...
A.1000, shown in full working condition on Milan fair April 1948 and produced from September the same year, thus being on the market one year before the east German Zeiss Ikon VEB Contax S, announced on May 20, 1949, produced from September. The Japanese adopted and further developed the SLR. In 1952,
Asahi Asahi (朝日, 旭, or あさひ) means "morning sun" in Japanese and may refer to: Cities * Asahi, Chiba (旭市; ''Asahi-shi'') Wards * Asahi-ku, Osaka (旭区; ''Asahi-ku'') * Asahi-ku, Yokohama (旭; ''Asahi-ku'') Towns * Asahi, Aichi (旭 ...
developed the
Asahiflex The Asahiflex was a 35 mm single-lens reflex camera built by the Asahi Optical Corporation (later to become Pentax). It was regarded as the first SLR camera built in Japan. Asahi Optical introduced its first 35 mm camera in 1952. Unlike t ...
and in 1954, the
Asahiflex IIB The Asahiflex was a 35 mm single-lens reflex camera built by the Asahi Optical Corporation (later to become Pentax). It was regarded as the first SLR camera built in Japan. Asahi Optical introduced its first 35 mm camera in 1952. Unlike t ...
. In 1957, the
Asahi Pentax The Asahi Pentax series, by the , was a pivotal development in modern photography. They were the earliest Pentax cameras. Background In 1957, the Asahi Optical Company (later "Pentax") introduced the Pentax, a 135 film, 35 mm Single-lens ...
combined the fixed pentaprism and the right-hand thumb wind lever.
Nikon (, ; ), also known just as Nikon, is a Japanese multinational corporation headquartered in Tokyo, Japan, specializing in optics and imaging products. The companies held by Nikon form the Nikon Group. Nikon's products include cameras, camera ...
,
Canon Canon or Canons may refer to: Arts and entertainment * Canon (fiction), the conceptual material accepted as official in a fictional universe by its fan base * Literary canon, an accepted body of works considered as high culture ** Western ca ...
and
Yashica Yashica was a Japanese manufacturer of cameras, originally active from 1949 until 2005 when its then-owner, Kyocera, ceased production. In 2008, the Yashica name reappeared on cameras produced by the Hong Kong-based MF Jebsen Group. In 2015, t ...
introduced their first SLRs in 1959 (the F, Canonflex, and Pentamatic, respectively).


Through-the-lens light metering

As a small matter of history, the first 35 mm camera (non-SLR) to feature through the lens light metering may have been Nikon, with a prototype rangefinder camera, the SPX. According to the website below, the camera used Nikon 'S' type rangefinder lenses. Through-the-lens light metering is also known as "behind-the-lens metering". In the SLR design scheme, there were various placements made for the metering cells, all of which used CdS (
Cadmium sulfide Cadmium sulfide is the inorganic compound with the formula CdS. Cadmium sulfide is a yellow solid.Egon Wiberg, Arnold Frederick Holleman (2001''Inorganic Chemistry'' Elsevier It occurs in nature with two different crystal structures as the rare mi ...
) photocells. The cells were either located in the pentaprism housing, where they metered light transmitted through the focusing screen; underneath the reflex mirror glass itself, which was Topcon's design; or in front of the shutter mechanism, which was the design used by Canon with their Canon Pellix. Pentax was the first manufacturer to show an early prototype 35 mm behind-the-lens metering SLR camera, which was named the ''
Pentax Spotmatic The Pentax Spotmatic refers to a family of 35mm single-lens reflex cameras manufactured by the Asahi Optical Co. Ltd., later known as Pentax Corporation, between 1964 and 1976. All Pentax Spotmatics used the M42 screw-thread lens mount which w ...
''. The camera was shown at the 1960 photokina show. However, the first
Through-the-lens In photography, through-the-lens metering (TTL metering) refers to a feature of cameras whereby the intensity of light reflected from the scene is measured through the lens; as opposed to using a separate metering window or external hand-held light ...
(TTL)
light meter A light meter is a device used to measure the amount of light. In photography, a light meter (more correctly an exposure meter) is used to determine the proper exposure (photography), exposure for a photograph. The meter will include either a Di ...
ing SLR on the market was the 1963
Topcon RE Super The Topcon RE Super, or Beseler Topcon Super D in USA, was launched by Tokyo Kogaku KK in 1963 and manufactured until 1971, at which point it was upgraded to the ''Super D'' and again to ''Super DM'' the following year. General sale continued for ...
, which had the CdS metering cell placed behind the reflex mirror. The mirror had narrow slits cut into the surface to let the light reach the cell providing
average metering In photography, the metering mode refers to the way in which a camera determines exposure. Cameras generally allow the user to select between ''spot'', ''center-weighted average'', or ''multi-zone'' metering modes. The different metering modes all ...
. Late in the following year, a production model of the Pentax Spotmatic was shown whose CdS light meter cells were on the pentaprism, reading the light off the focusing screen providing average reading, yet keeping the Spotmatic name, but now written in one word. Another clever design appeared in 1965, the Canon Pellix employing a
pellicle mirror A pellicle mirror is an ultra-thin, ultra-lightweight semi-transparent mirror employed in the light path of an optical instrument, splitting the light beam into two separate beams, both of reduced light intensity. Splitting the beam allows its use ...
that is semi-transparent, placing the meter cell on an arm swinging into the lightpass behind the mirror for meter reading. Mamiya Sekor came out with cameras such as the Mamiya Sekor TL and various other versions. Yashica introduced the TL Super. Both of these cameras used M42 screw thread lenses as did the Pentax Spotmatic. Later on Fujica introduced their ST-701, then ST-801 and ST-901 cameras. The ST-701 was the first SLR to use a silicon cell photodiode, which was more sensitive than CdS and was immune to the memory effect that the CdS cell suffered from in bright sunlight. Gradually, other 35 mm SLR camera manufacturers changed their behind-the-lens meters from CdS cells to Silicon Diode photocells. Other manufacturers responded and introduced their own behind-the-lens metering cameras. Nikon and Miranda, at first, simply upgraded their interchangeable pentaprisms to include behind-the-lens metering (for Nikon F, and Miranda D, F, Fv and G models) and these manufacturers also bought out other camera models with built-in behind-the-lens metering capability, such as the Nikkormat FT and the Miranda Sensorex (which used an external coupling diaphragm). Minolta introduced the SRT-101, which used Minolta's proprietary system they referred to as "CLC", which was an acronym for "contrast light compensation", which metered differently from an average metering behind-the-lens camera. Some German manufacturers also introduced cameras such as the Zeiss Ikon Contarex family, which was one of very few 35 mm SLR to use interchangeable film backs. Inexpensive leaf-shutter cameras also benefited from behind-the-lens metering as, Topcon introduced the Auto 100 with front-mount interchangeable lenses designed only for that camera, and one of the Zeiss Ikon Contaflex leaf shutter cameras. Kowa manufactured their SET-R, which had similar specifications. Within months, manufacturers decided to bring out models that provided limited area metering, such as Nikon's Photomic Tn finder, which concentrated 60% of the CdS cells sensitivity on the inner circle of the focusing screen and 30% on the surrounding area. Canon used spot metering in the unusual Canon Pellix camera, which also had a stationary mirror system that allowed approximately 70% of the light to travel to the film plane and 30% to the photographer's eye. This system, unfortunately, degraded the native resolution of the attached lens and provided less illumination to the eyepiece. It did have the advantage of having less vibration than other SLR cameras but this was not sufficient to attract professionals to the camera in numbers.


Semi-automatic exposure capabilities

While auto-exposure was commonly used in the early 1960s with various 35 mm fixed lens rangefinder cameras such as the Konica Auto 'S', and other cameras such as the Polaroid Land cameras whose early models used selenium cell meters, auto-exposure for interchangeable lens SLRs was a feature that was largely absent, except for a few early leaf-shutter SLRs such as the Kowa SE-R and Topcon Auto 100. The types of automation found in some of these cameras consisted of the simple programmed shutter, whereby the camera's metering system would select a mechanically set series of apertures with shutter speeds, one setting of which would be sufficient for the correct exposure. In the case of the above-mentioned Kowa and Topcon, automation was semi-automatic, where the camera's CDs meter would select the correct aperture only. Autoexposure, technically known as semi-automatic exposure, where the camera's metering system chooses either the shutter speed or the aperture, was finally introduced by the Savoyflex and popularized by
Konishiroku was a Japanese manufacturer of, among other products, film, film cameras, camera accessories, photographic and photo-processing equipment, photocopiers, fax machines and laser printers, founded in 1873. The company merged with Japanese peer Min ...
in the 1965
Konica was a Japanese manufacturer of, among other products, film, film cameras, camera accessories, photographic and photo-processing equipment, photocopiers, fax machines and laser printers, founded in 1873. The company merged with Japanese peer M ...
Auto-Reflex. This camera was of the 'shutter-priority' type automation, which meant that the camera selected the correct aperture automatically. This model also had the interesting ability to photograph in 35 mm full-frames or half-frames, all selected by a lever. Other SLRs soon followed, but because of limitations with their lens mounts, the manufacturers of these cameras had to choose 'aperture-priority' automation, where the camera's metering system selects the correct shutter speed. As one example, Pentax introduced the Electro Spotmatic, which was able to use the then considerable bulk of 42 mm screw-mount lenses produced by various manufacturers. Yashica, another screw-mount camera manufacturer, soon followed. Canon, which produced the FD lens mount (known as the breech-mount; a unique lens mounting system that combines the advantages of screw-mount and bayonet-mount) introduced their shutter priority 35 mm SLR, the Canon EF in 1976 or so. This camera's build quality was almost the equal of their flagship camera, the Canon F1, and featured a copal-square vertically travelling focal plane shutter that could synchronize electronic flash at shutter speeds up to and including 1/125 of a second, thus making this a good second-body camera for the professional photographer. Nikon at first produced an aperture-priority camera, but later made subtle changes on the inside of their bayonet mount, which allowed for shutter-priority automation without obsoleting the photographers lenses.


Full-program auto-exposure

Full-program auto-exposure soon followed with the advent of the Canon A-1 in 1978. This SLR had a 'P' mode on the shutter speed dial, and a lock on the aperture ring to allow the lens to be put on 'Auto' mode. Other manufacturers soon followed with Nikon introducing the FA, Minolta introducing the X-700 in 1981, and Pentax introducing the Super Program. Olympus, however, continued with 'aperture-priority' automation in their OM system line. The 1970s and 1980s saw steadily increasing use of electronics, automation, and miniaturization, including integrated
motor drive Motor drive means a system that includes a motor. An adjustable speed motor drive means a system that includes a motor that has multiple operating speeds. A variable speed motor drive is a system that includes a motor and is continuously variabl ...
n film advance with the
Konica FS-1 was a Japanese manufacturer of, among other products, film, film cameras, camera accessories, photographic and photo-processing equipment, photocopiers, fax machines and laser printers, founded in 1873. The company merged with Japanese peer Mino ...
in 1979, and motor rewind functions.


Autofocus

The first
autofocus An autofocus (or AF) optical system uses a sensor, a control system and a motor to focus on an automatically or manually selected point or area. An electronic rangefinder has a display instead of the motor; the adjustment of the optical system ...
35 mm SLR was the
Pentax ME-F is a brand name used primarily by the Japanese multinational imaging and electronics company Ricoh for DSLR cameras, lenses, sport optics (including binoculars and rifle scopes), and CCTV optics. The Pentax brand is also used by Hoya Corporatio ...
released in 1981. The
Minolta Maxxum 7000 The Minolta MAXXUM 7000 (7000 AF in Europe and α-7000 in Japan) 35 mm SLR camera was introduced in February 1985. It was the first camera to feature both integrated autofocus (AF) and motorised film advance, the standard configuration for later ...
, released in 1985, was the first 35 mm SLR with integrated autofocus and motorized film-advance winder, which became the standard configuration for SLR cameras from then on. This development had significant impact on the photographic industry. Some manufacturers discarded their existing lens systems to compete with other manufacturer's autofocus capability in their new cameras. This was the case for Canon, with its new EOS lens line. Other manufacturers chose to adapt their existing lens systems for autofocus capability, as was the case with Nikon and Pentax. This allowed photographers to continue using their existing lenses, which greatly reduced the cost of upgrading. For example, almost all Nikon lenses from the 1960s and later still function on the current Nikon bodies, only lacking autofocus. Still some manufacturers, notably Leica with its R-system lenses, and Contax with its Zeiss lenses, decided to keep their lens mounts non-autofocus. From the late 1980s competition and technical innovations made 35 mm camera systems more versatile and sophisticated by adding more advanced light metering capabilities such as spot-metering; limited area metering such as used by Canon with the F1 series; matrix metering as used by Nikon, exposure communication with dedicated electronic flash units. The user interface also changed on many cameras, replacing meter needle displays that were galvanometer-based and thereby fragile, with
light-emitting diodes A light-emitting diode (LED) is a semiconductor device that emits light when current flows through it. Electrons in the semiconductor recombine with electron holes, releasing energy in the form of photons. The color of the light (cor ...
(LEDs) and then with more comprehensive liquid crystal displays (LCDs) both in the SLR viewfinder and externally on the cameras' top plate using an LCD screen. Wheels and buttons replaced the shutter dial on the camera and the aperture ring on the lens on many models, although some photographers still prefer shutter dials and aperture rings. Some manufacturers introduced image stabilization on certain lenses to combat camera shake and to allow longer hand-held exposures without using a tripod. This feature is especially useful with long telephoto lenses.


Digital SLRs

Canon, Nikon and
Pentax is a brand name used primarily by the Japanese multinational imaging and electronics company Ricoh for DSLR cameras, lenses, sport optics (including binoculars and rifle scopes), and CCTV optics. The Pentax brand is also used by Hoya Corporatio ...
have all developed digital SLR cameras (DSLRs) using the same lens mounts as on their respective film SLR cameras. Konica Minolta did the same, and after having bought Konica Minolta's camera division in 2006 Sony continue using the Minolta AF lens mount in their DSLRs, including cameras built around a semi-transparent fixed mirror. Samsung builds DSLRs based on the
Pentax is a brand name used primarily by the Japanese multinational imaging and electronics company Ricoh for DSLR cameras, lenses, sport optics (including binoculars and rifle scopes), and CCTV optics. The Pentax brand is also used by Hoya Corporatio ...
lens mount. Olympus, on the other hand, chose to create a new digital-only
Four Thirds System The Four Thirds System is a standard created by Olympus and Eastman Kodak for digital single-lens reflex camera (DSLR) and mirrorless camera design and development. The system provides a standard that, with digital cameras and lenses availa ...
SLR standard, adopted later by Panasonic and Leica. Contax came out with a DSLR model, the Contax N-Digital. This model was too late and too expensive to be competitive with other camera manufacturers. The Contax N-digital was the last Contax to use that maker's lens system, and the camera, while having impressive features such as a full-frame sensor, was expensive and lacked sufficient write-speed to the memory card for it to be seriously considered by some professional photographers. The digital single-lens reflex camera have largely replaced film SLRs design in convenience, sales and popularity at the start of 21st century.


Optical components

A cross-section (''or'' 'side-view') of the optical components of a typical SLR camera shows how the light passes through the lens assembly (1), is reflected by the mirror (2) placed at a 45-degree angle, and is projected on the matte focusing screen (5). Via a condensing lens (6) and internal reflections in the roof pentaprism (7) the image appears in the eyepiece (8). When an image is taken, the mirror moves upwards from its resting position in the direction of the arrow, the focal plane shutter (3) opens, and the image is projected onto the
film A film also called a movie, motion picture, moving picture, picture, photoplay or (slang) flick is a work of visual art that simulates experiences and otherwise communicates ideas, stories, perceptions, feelings, beauty, or atmosphere ...
or sensor (4) in exactly the same manner as on the focusing screen. This feature distinguishes SLRs from other cameras as the photographer sees the image composed exactly as it will be captured on the film or sensor (see
Advantages Advantage may refer to: * Advantage (debate), an argument structure in competitive debate * Mechanical advantage, in engineering, the ratio of output force to input force on a system * Advantage of terrain, in military use, a superiority in el ...
below).


Pentaprisms and penta-mirrors

Most 35 mm SLRs use a roof
pentaprism A pentaprism is a five-sided reflecting prism used to deviate a beam of light by a constant 90°, even if the entry beam is not at 90° to the prism. The beam reflects inside the prism ''twice'', allowing the transmission of an image through a r ...
or penta-mirror to direct the light to the eyepiece, first used on the 1948 Duflex constructed by Jenő Dulovits and patented August 1943 (Hungary). With this camera also appeared the first Instant-return mirror. The first Japanese pentaprism SLR was the 1955 Miranda T, followed by the Asahi Pentax, Minolta SR-2, Zunow, Nikon F and the
Yashica Yashica was a Japanese manufacturer of cameras, originally active from 1949 until 2005 when its then-owner, Kyocera, ceased production. In 2008, the Yashica name reappeared on cameras produced by the Hong Kong-based MF Jebsen Group. In 2015, t ...
Pentamatic. Some SLRs offered removable pentaprisms with optional viewfinder capabilities, such as the waist-level finder, the interchangeable sports finders used on the Canon F1 and F1n; the
Nikon (, ; ), also known just as Nikon, is a Japanese multinational corporation headquartered in Tokyo, Japan, specializing in optics and imaging products. The companies held by Nikon form the Nikon Group. Nikon's products include cameras, camera ...
F, F2, F3, F4 and F5; and the Pentax LX. Another prism design was the
porro prism In optics, a Porro prism, named for its inventor Ignazio Porro, is a type of ''reflection prism'' used in optical instruments to alter the orientation of an image. Description It consists of a block of material shaped like a right geometric ...
system used in the
Olympus Pen F The Olympus Pen F, Pen FT and Pen FV are very similar half-frame 35 mm single-lens reflex (SLR) cameras with interchangeable lenses produced by Olympus of Japan between 1963-1966 (Pen F), 1966-1972 (Pen FT) and 1967-1970 (Pen FV). The ori ...
, the Pen FT, the Pen FV half-frame 35 mm SLR cameras. This was later used on the Olympus EVOLT E-3x0 series, the Leica Digilux 3 and the Panasonic DMC-L1. A right-angle finder is available that slips onto the eyepiece of most SLRs and D-SLRs and allows viewing through a waist-level viewfinder. There is also a finder that provides EVF remote capability.


Shutter mechanisms


Focal-plane shutters

Almost all contemporary SLRs use a
focal-plane shutter In camera design, a focal-plane shutter (FPS) is a type of photographic shutter that is positioned immediately in front of the focal plane of the camera, that is, right in front of the photographic film or image sensor. Two-curtain shutters ...
located in front of the film plane, which prevents the light from reaching the film even if the lens is removed, except when the shutter is actually released during the exposure. There are various designs for focal plane shutters. Early focal-plane shutters designed from the 1930s onwards usually consisted of two curtains that travelled horizontally across the film gate: an opening shutter curtain followed by a closing shutter curtain. During fast shutter speeds, the focal-plane shutter would form a 'slit' whereby the second shutter curtain was closely following the first opening shutter curtain to produce a narrow, vertical opening, with the shutter slit moving horizontally. The slit would get narrower as shutter speeds were increased. Initially these shutters were made from a cloth material (which was in later years often rubberised), but some manufacturers used other materials instead. Nippon Kōgaku (now
Nikon Corporation (, ; ), also known just as Nikon, is a Japanese multinational corporation headquartered in Tokyo, Japan, specializing in optics and imaging products. The companies held by Nikon form the Nikon Group. Nikon's products include cameras, camera ...
), for example, used
titanium Titanium is a chemical element with the symbol Ti and atomic number 22. Found in nature only as an oxide, it can be reduced to produce a lustrous transition metal with a silver color, low density, and high strength, resistant to corrosion in ...
foil shutters for several of their flagship SLR cameras, including the
Nikon F The Nikon F camera, introduced in April 1959, was Nikon's first SLR camera. It was one of the most advanced cameras of its day. Although many of the concepts had already been introduced elsewhere, it was revolutionary in that it was the firs ...
, F2, and F3. Other focal-plane shutter designs, such as the
Copal Copal is tree resin, particularly the aromatic resins from the copal tree ''Protium copal'' (Burseraceae) used by the cultures of pre-Columbian Mesoamerica as ceremonially burned incense and for other purposes. More generally, copal includes re ...
Square, travelled vertically — the shorter travelling distance of 24 millimetres (as opposed to 36 mm horizontally) meant that minimum exposure and flash synchronisation times could be reduced. These shutters are usually manufactured from metal, and use the same moving-slit principle as horizontally travelling shutters. They differ, though, in usually being formed of several slats or blades, rather than single curtains as with horizontal designs, as there is rarely enough room above and below the frame for a one-piece shutter. Vertical shutters became very common in the 1980s (though
Konica was a Japanese manufacturer of, among other products, film, film cameras, camera accessories, photographic and photo-processing equipment, photocopiers, fax machines and laser printers, founded in 1873. The company merged with Japanese peer M ...
,
Mamiya is a Japanese company that manufactures high-end cameras and other related photographic and optical equipment. With headquarters in Tokyo, it has two manufacturing plants and a workforce of over 200 people. The company was founded in May 1940 b ...
, and Copal first pioneered their use in the 1950s and 1960s, and are almost exclusively used for new cameras. Nikon used Copal-made vertical plane shutters in their Nikomat/Nikkormat -range, enabling x-sync speeds from to while the only choice for focal plane shutters at that time was . Later, Nikon again pioneered the use of titanium for vertical shutters, using a special honeycomb pattern on the blades to reduce their weight and achieve world-record speeds in 1982 of second for non-sync shooting, and with x-sync. Nowadays most such shutters are manufactured from cheaper aluminium (though some high-end cameras use materials such as
carbon-fibre Carbon fiber-reinforced polymers (American English), carbon-fibre-reinforced polymers (Commonwealth English), carbon-fiber-reinforced plastics, carbon-fiber reinforced-thermoplastic (CFRP, CRP, CFRTP), also known as carbon fiber, carbon compo ...
and
Kevlar Kevlar (para-aramid) is a strong, heat-resistant synthetic fiber, related to other aramids such as Nomex and Technora. Developed by Stephanie Kwolek at DuPont in 1965, the high-strength material was first used commercially in the early 1970s a ...
).


Rotary focal-plane shutter

One unusual design, the
Olympus Pen The Pen, or PEN series is a brand of Olympus. It was used on analog half-frame compact and SLR models from 1959 until the early 1980s. In 2009, Olympus released the PEN E-P1, a digital mirrorless interchangeable-lens camera, which opened the rang ...
half-frame 35 mm SLR system, manufactured by Olympus in Japan, used a rotary focal-plane shutter mechanism that was extremely simple and elegant in design. This shutter used titanium foil but consisted of one piece of metal with a fixed opening, which allowed electronic flash synchronisation up to and including its maximum speed of 1/500 of a second – rivalling the capabilities of leaf-shutter systems Another 35 mm camera system that used a rotary shutter, was the Robot Royal cameras, most of which were rangefinder 35 mm cameras. Some of these cameras were full-frame; some were half-frame, and at least one Robot camera produced an unusual square-sized image on the 35 mm frame. The Mercury II, produced in 1946, also used a rotary shutter. This was a half-frame 35 mm camera.


Leaf shutters

Another shutter system is the
leaf shutter In photography, a shutter is a device that allows light to pass for a determined period, exposing photographic film or a photosensitive digital sensor to light in order to capture a permanent image of a scene. A shutter can also be used to allow ...
, whereby the shutter is constructed of diaphragm-like blades and can be situated either between the lens or behind the lens. If the shutter is part of a lens assembly some other mechanism is required to ensure that no light reaches the film between exposures. An example of a behind-the-lens leaf shutter is found in the 35 mm SLRs produced by
Kodak The Eastman Kodak Company (referred to simply as Kodak ) is an American public company that produces various products related to its historic basis in analogue photography. The company is headquartered in Rochester, New York, and is incorpor ...
, with their Retina Reflex camera line; Topcon, with their Auto 100; and Kowa with their SE-R and SET-R reflexes. A primary example of a medium-format SLR with a between-the-lens leaf shutter system would be
Hasselblad Victor Hasselblad AB is a Swedish manufacturer of medium format cameras, photographic equipment and image scanners based in Gothenburg, Sweden. The company originally became known for its classic analog medium-format cameras that used a waist ...
, with their 500C, 500 cm, 500 EL-M (a motorized Hasselblad) and other models (producing a 6 cm square negative). Hasselblads use an auxiliary shutter blind situated behind the lens mount and the mirror system to prevent the fogging of film. Other medium-format SLRs also using leaf shutters include the now discontinued Zenza-Bronica camera system lines such as the Bronica ETRs, the ETRs'i (both producing a 6 × 4.5 cm. image), the SQ and the SQ-AI (producing a 6 × 6 cm image like the Hasselblad), and the Zenza-Bronica G system (6 × 7 cm). Certain Mamiya medium-format SLRs, discontinued camera systems such as the Kowa 6 and a few other camera models also used between-the-lens leaf shutters in their lens systems. Thus, any time a photographer purchased one of these lenses, that lens included a leaf shutter in its lens mount. Because leaf shutters synchronized electronic flash at all shutter speeds especially at fast shutter speeds of of a second or faster, cameras using leaf shutters were more desirable to studio photographers who used sophisticated studio electronic flash systems. Some manufacturers of medium-format
120 film 120 is a film format for still photography introduced by Kodak for their '' Brownie No. 2'' in 1901. It was originally intended for amateur photography but was later superseded in this role by 135 film. 120 film survives to this day as the only ...
SLR cameras also made leaf-shutter lenses for their focal-plane-shutter models. Rollei made at least two such lenses for their Rolleiflex SL-66 medium format which was a focal-plane shutter SLR. Rollei later switched to a camera system of leaf-shutter design (e.g., the 6006 and 6008 reflexes) and their current medium-format SLRs are now all of the between-the-lens shutter design.


Further developments

Since the technology became widespread in the 1970s, SLRs have become the main photographic instrument used by dedicated amateur photographers and professionals. Some photographers of static subjects (such as architecture, landscape, and some commercial subjects), however, prefer
view camera A view camera is a large-format camera in which the lens forms an inverted image on a ground-glass screen directly at the film plane. The image is viewed and then the glass screen is replaced with the film, and thus the film is exposed to exact ...
s because of the capability to control perspective. With a triple-extension bellows 4" × 5" camera such as the Linhof SuperTechnika V, the photographer can correct certain distortions such as "keystoning", where the image 'lines' converge (i.e., photographing a building by pointing a typical camera upward to include the top of the building).
Perspective correction lens Perspective may refer to: Vision and mathematics * Perspectivity, the formation of an image in a picture plane of a scene viewed from a fixed point, and its modeling in geometry ** Perspective (graphical), representing the effects of visual persp ...
es are available in the 35 mm and medium formats to correct this distortion with film cameras, and it can also be corrected after the fact with photo software when using digital cameras. The photographer can also extend the bellows to its full length, tilt the front standard and perform photomacrography (commonly known as ' macro photography'), producing a sharp image with depth-of-field without stopping down the lens diaphragm.


Film formats

Early SLRs were built for
large format Large format refers to any imaging format of or larger. Large format is larger than "medium format", the or size of Hasselblad, Mamiya, Rollei, Kowa, and Pentax cameras (using 120- and 220-roll film), and much larger than the frame ...
photography, but this film format has largely lost favor among professional photographers. SLR film-based cameras have been produced for most
film format A film format is a technical definition of a set of standard characteristics regarding image capture on photographic film for still images or film stock for filmmaking. It can also apply to projected film, either slides or movies. The primary ...
s as well as for digital formats. These film-based SLRs use the 35 mm format as, this film format offers a variety of emulsions and film sensitivity speeds, usable image quality and a good market cost. 35 mm film comes in a variety of exposure lengths: 20 exposure, 24 exposure and 36 exposure rolls.
Medium format Medium format has traditionally referred to a film format in photography and the related cameras and equipment that use film. Nowadays, the term applies to film and digital cameras that record images on media larger than the used in 35&nbs ...
SLRs provide a higher-quality image with a negative that can be more easily retouched than the smaller 35 mm negative, when this capability is required. A small number of SLRs were built for APS such as the Canon IX series and the Nikon Pronea cameras. SLRs were also introduced for film formats as small as Kodak's
110 110 may refer to: *110 (number), natural number *AD 110, a year *110 BC, a year *110 film, a cartridge-based film format used in still photography *110 (MBTA bus), Massachusetts Bay Transportation Authority bus route *110 (song), 2019 song by Capi ...
, such as the Pentax Auto 110, which had interchangeable lenses. The
Narciss camera The Narciss is an all-metal 16 mm subminiature single lens reflex camera made by Russian optic firm Krasnogorsky Mekhanichesky Zavod ( KMZ) Narciss (Soviet Union; Нарцисс) between 1961 and 1965. It is the first subminiature S ...
is an all-metal 16 mm subminiature single lens reflex camera made by Russian optic firm Krasnogorsky Mekhanichesky Zavod (KMZ) Narciss (Soviet Union; Нарцисс) between 1961 and 1965.


Common features

Other features found on many SLR cameras include through-the-lens (TTL) metering and sophisticated flash control referred to as "dedicated electronic flash". In a dedicated system, once the dedicated electronic flash is inserted into the camera's hot shoe and turned on, there is then communication between camera and flash. The camera's synchronization speed is set, along with the aperture. Many camera models measure the light that reflects off of the film plane, which controls the flash duration of the electronic flash. This is denoted TTL flash metering. Some electronic flash units can send out several short bursts of light to aid the autofocus system or for wireless communication with off-camera flash units. A pre-flash is often used to determine the amount of light that is reflected from the subject, which sets the duration of the main flash at time of exposure. Some cameras also employ automatic fill-flash, where the flash light and the available light are balanced. While these capabilities are not unique to the SLR, manufacturers included them early on in the top models, whereas the best rangefinder cameras adopted such features later.


Advantages

Many of the advantages of SLR cameras derive from viewing and focusing the image through the attached lens. Most other types of cameras do not have this function; subjects are seen through a viewfinder that is near the lens, making the photographer's view different from that of the lens. SLR cameras provide photographers with precision; they provide a viewing image that will be exposed onto the negative exactly as it is seen through the lens. There is no
parallax Parallax is a displacement or difference in the apparent position of an object viewed along two different lines of sight and is measured by the angle or semi-angle of inclination between those two lines. Due to foreshortening, nearby objects ...
error, and exact focus can be confirmed by eye—especially in macro photography and when photographing using
long focus lens In photography, a long-focus lens is a camera lens which has a focal length that is longer than the diagonal measure of the film or sensor that receives its image. It is used to make distant objects appear magnified with magnification increas ...
es. The
depth of field The depth of field (DOF) is the distance between the nearest and the furthest objects that are in acceptably sharp focus in an image captured with a camera. Factors affecting depth of field For cameras that can only focus on one object dist ...
may be seen by stopping down to the attached lens
aperture In optics, an aperture is a hole or an opening through which light travels. More specifically, the aperture and focal length of an optical system determine the cone angle of a bundle of rays that come to a focus in the image plane. An opt ...
, which is possible on most SLR cameras except for the least expensive models. Because of the SLR's versatility, most manufacturers have a vast range of lenses and accessories available for them. Compared to most fixed-lens compact cameras, the most commonly used and inexpensive SLR lenses offer a wider aperture range and larger maximum aperture (typically to for a 50 mm lens). This allows photographs to be taken in lower light conditions without flash, and allows a narrower depth of field, which is useful for blurring the background behind the subject, making the subject more prominent. "Fast" lenses are commonly used in theater photography, portrait photography, surveillance photography, and all other photography requiring a large maximum aperture. The variety of lenses also allows for the camera to be used and adapted in many different situations. This provides the photographer with considerably more control (i.e., how the image is viewed and framed) than would be the case with a view camera. In addition, some SLR lenses are manufactured with extremely long focal lengths, allowing a photographer to be a considerable distance away from the subject and yet still expose a sharp, focused image. This is particularly useful if the subject includes dangerous animals (e.g., wildlife); the subject prefers anonymity to being photographed; or else, the photographer's presence is unwanted (e.g., celebrity photography or surveillance photography). Practically all SLR and DSLR camera bodies can also be attached to telescopes and microscopes via an adapter tube to further enhance their imaging capabilities.


Disadvantages

In most cases, single-lens reflex cameras cannot be made as small or as light as other camera designs—such as
rangefinder camera A rangefinder camera is a camera fitted with a rangefinder, typically a split-image rangefinder: a range-finding focusing mechanism allowing the photographer to measure the subject distance and take photographs that are in sharp focus. Most va ...
s, autofocus compact cameras and digital cameras with
electronic viewfinder An electronic viewfinder (EVF) is a camera viewfinder where the image captured by the lens is displayed on a small screen (usually LCD or OLED) which the photographer can look through when composing their shot. It differs from a live preview ...
s (EVF)—owing to the mirror box and pentaprism/pentamirror. The mirror box also prevents lenses with deeply recessed rear elements from being mounted close to the film or sensor unless the camera has a mirror lockup feature; this means that simple designs for
wide angle lens In photography and cinematography, a wide-angle lens refers to a lens whose focal length is substantially smaller than the focal length of a normal lens for a given film plane. This type of lens allows more of the scene to be included in the ph ...
es cannot be used. Instead, larger and more complex retrofocus designs are required. The SLR mirror 'blacks-out' the viewfinder image during the exposure. In addition, the movement of the reflex mirror takes time, limiting the maximum shooting speed. The mirror system can also cause noise and vibration. Partially reflective (pellicle) fixed mirrors avoid these problems and have been used in a very few designs including the
Canon Pellix The Canon Pellix is a manual-focus single-lens reflex (SLR) camera released in 1965 that uses a stationary half-silvered mirror behind which a metering cell is raised during light level metering. The First Canon with TTL Canon suddenly switche ...
and the Canon EOS-1N RS, but these designs introduce their own problems. These pellicle mirrors reduce the amount of light travelling to the film plane or sensor and also can distort the light passing through them, resulting in a less-sharp image. To avoid the noise and vibration, many professional cameras offer a
mirror lock-up Mirror lock-up (often abbreviated to MLU) is a feature employed in many Single Lens Reflex (SLR) cameras. It allows the operator to reduce vibration-induced motion blur during exposure. It also allows the mounting of lenses which extend into th ...
feature, however, this feature totally disables the SLR's automatic focusing ability. Electronic viewfinders have the potential to give the 'viewing-experience' of a DSLR (through-the-lens viewing) without many of the disadvantages. More recently,
Sony , commonly stylized as SONY, is a Japanese multinational conglomerate corporation headquartered in Minato, Tokyo, Japan. As a major technology company, it operates as one of the world's largest manufacturers of consumer and professional ...
have resurrected the pellicle mirror concept in their " single-lens translucent" (SLT) range of cameras.


Reliability

SLRs vary widely in their construction and typically have bodies made of plastic or magnesium. Most manufacturers do not cite durability specifications, but some report shutter life expectancies for professional models. For instance, the Canon EOS 1Ds MkII is rated for 200,000 shutter cycles and the Nikon D3 is rated for 300,000 with its exotic carbon fiber/kevlar shutter. Because many SLRs have interchangeable lenses, there is a tendency for dust, sand and dirt to get into the main body of the camera through the mirror box when the lens is removed, thus dirtying or even jamming the mirror movement mechanism or the shutter curtain mechanism itself. In addition, these particles can also jam or otherwise hinder the focusing feature of a lens if they enter into the focusing helicoid. The problem of sensor cleaning has been somewhat reduced in
DSLR A digital single-lens reflex camera (digital SLR or DSLR) is a digital camera that combines the optics and the mechanisms of a single-lens reflex camera with a digital imaging sensor. The reflex design scheme is the primary difference between a ...
s as some cameras have a built-in sensor cleaning unit.


Price and affordability

The price of SLRs in general also tends to be somewhat higher than that of other types of cameras, owing to their internal complexity. This is compounded by the expense of additional components, such as flashes or lenses. The initial investment in equipment can be prohibitive enough to keep some casual photographers away from SLRs, although the market for used SLRs has become larger particularly as photographers migrate to digital systems.


Future

The digital single-lens reflex camera has largely replaced the film SLR for its convenience, sales, and popularity at the start of 21st century. These cameras are currently the marketing favorite among advanced amateur and professional photographers. Film-based SLRs are still used by a niche market of enthusiasts and format lovers.


See also

*
Asahi Pentax The Asahi Pentax series, by the , was a pivotal development in modern photography. They were the earliest Pentax cameras. Background In 1957, the Asahi Optical Company (later "Pentax") introduced the Pentax, a 135 film, 35 mm Single-lens ...
*
Fujifilm , trading as Fujifilm, or simply Fuji, is a Japanese multinational conglomerate headquartered in Tokyo, Japan, operating in the realms of photography, optics, office and medical electronics, biotechnology, and chemicals. The offerings from the ...
*
Lenses for SLR and DSLR cameras This article is about photographic lenses for single-lens reflex film cameras (SLRs) and digital single-lens reflex cameras (DSLRs). Emphasis is on modern lenses for 35 mm film SLRs and for DSLRs with sensor sizes less than or equal to 3 ...
*
Scheimpflug principle The Scheimpflug principle is a description of the geometric relationship between the orientation of the plane of focus, the lens plane, and the image plane of an optical system (such as a camera) when the lens plane is not parallel to the imag ...
*
Zeiss Ikon Carl Zeiss AG (), branded as ZEISS, is a German manufacturer of optical systems and optoelectronics, founded in Jena, Germany in 1846 by optician Carl Zeiss. Together with Ernst Abbe (joined 1866) and Otto Schott (joined 1884) he laid the ...


References


Further reading

* Spira, S. F. ''The History of Photography as Seen through the Spira Collection.'' New York: Aperture, 2001. . * Antonetto, Marco: "Rectaflex – The Magic Reflex". Nassa Watch Gallery, 2002.


External links

* Photography in Malaysia'
Contax History, Part II



Rolleiflex SL 66
(Rolleiflex SL 66 Medium Format Single Lens Reflex camera). {{Authority control Cameras by type
SLR cameras SLR may refer to: Science and technology * Satellite laser ranging * Scalable Linear Recording tape drive backup * Sea level rise * Self-loading rifle or semi-automatic rifle ** The UK L1A1 SLR rifle * Semi-linear resolution, a search algorith ...