The Canon TX was a 35mm single-lens reflex camera manufactured by Canon of Japan from March 1975. It featured a Canon FD lens mount, was compatible with Canon's earlier FL-mount lenses in stop-down metering mode; the TX was a cheaper version of the Canon FTb for the export market, as was the earlier TLb. Compared to the TLb, the TX had a hot shoe for flash. Compared to the FTb, the TX had a top shutter speed of only 1/500; the meter was center-weighted rather than the 12% partial meter of the FTb. It dispensed with the self-timer and MLU of the FTb, although it did retain the depth of field preview lever and support for stopped-down metering; the TX did not support the CAT flash system. It was sold in the US as the Bell & Howell FD35
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 for multiple purposes simultaneously; the thinness of the mirror eliminates beam or image doubling due to a non-coincident weak second reflection from the nominally non-reflecting surface, a problem with mirror-type beam splitters. In photography, the pellicle mirror has been employed in single-lens reflex cameras, at first to enable through-the-lens exposure measurement and to reduce camera shake, but most to enable fast series photography, which otherwise would be slowed down by the movement of the reflex mirror, while maintaining constant finder vision; the first use of pellicle mirrors for consumer photography however where in color separation cameras. The Devin Tricolor Camera from at least the 1938 version used two pellicle mirrors plus three color filters to split the image from a single lens into three images of the three additive primary colors.
Pellicle mirrors are ideal for this purpose today, since they are lighter and cheaper than an optical block of dichroic prisms, which would be heavy and expensive for large, high resolution film or plates. The conventional SLR camera has a reflex mirror directing the light beam from the lens to the focusing screen in the viewfinder, swung out of the light path when the exposure is made and causing the viewfinder to go dark; this action adds a delay between pressing the actual exposure of the film. The first camera to employ the pellicle mirror as a beam splitter for the viewfinder was the Canon Pellix, launched by Canon Camera Company Inc. Japan in 1965; the object was to accomplish exposure measurement through the lens, pioneered by Tokyo Kogaku KK, Japan in the 1963 Topcon RE Super. That employed a CdS meter cell placed behind the reflex mirror that had narrow slits cut into the surface to let the light reach the cell. Canon fixed; the meter cell was swung into the light-path behind the mirror by operating a lever on the right-hand camera front for stopped down exposure reading, momentarily dimming the viewfinder.
Two thirds of the light from the camera lens was let through the mirror, while the rest was reflected up to the viewfinder screen. The Pellix pellicle mirror was an ultra-thin Mylar film with a vapour deposited semi reflecting layer. Since there was no mirror blackout, the user could see the image at the moment of exposure; the next 35mm SLR camera to employ the pellicle mirror was the Canon F-1 High Speed, made available in the event of the 1972 Olympic games, the object being rapid series photography, difficult at the time to obtain with a moving mirror. The mirror design was the same as in the Pellix. In 1984, Canon released another version of their "New F-1", which attained a record 14 frames per second performance, being the fastest analog SLR of that time. Nippon Kogaku KK, Japan introduced their high-speed Nikon F2H in 1976; the mirror is a pellicle rather than a conventional front surfaced mirror that swings out of the light path when the exposure is made. To identify the F2H, note the shutter speed dial has no T, B or 1/2000.
Two further Canon models were produced with pellicle mirrors, the EOS RT and the EOS-1N RS, the RT being based on the EOS 600/EOS 630 and the 1N RS being based on the EOS-1N. As development of SLR cameras has progressed since these early models, fast sequence shooting has become possible using ordinary moving mirrors in high-speed cameras, getting rid of the vulnerable pellicle mirror, prone to dust and dirt; the mirror mechanism of conventional SLR cameras has improved since the Pellix mirror was introduced. Digital SLR cameras are able to take ten frames or more per second employing an instant-return mirror. Sony has introduced cameras with plastic pellicle-like mirrors, which it describes as "Single-Lens Translucent" cameras; these cameras divert a portion of incoming light to a phase-detection autofocus unit, while the remaining light strikes a digital image sensor. Sony "SLT" cameras employ an electronic viewfinder allowing exposure value, white balance and other settings to be verified and adjusted visually before taking a picture, although the EVF displays far less dynamic range than the sensor.
The refresh rate of the viewfinder is limited by the time it takes the sensor to make a usable exposure. "SLT" cameras lack a real-time view at high shooting rates, when the viewfinder shows the last picture taken instead of the one being taken — a phenomenon comparable to certain older SLRs that can only achieve their maximum burst rate in mirror lock-up. Few film movie cameras have been made; the earliest is the Pathé WEBO M, m for membrane, of 1946. With that camera light is reflexed sideways into a primary plano-convex finder lens, the plane side being or matted. Another French amateur movie camera with a pellicle is the Christen Reflex for Double-Eight film, it was made from 1960 on and provides a slanted deflection. In 1967, the professional Mitchell NCR and BNCR cameras were equipped with a pellicle-based finder. In the Soviet Union in 1970 appeared the Kiev 16 Alpha featuring a pellicle mirror finder system that deflects str
The 35 mm format, or 35 mm, is the common name for the 36×24 mm film format or image sensor format used in photography. It has an aspect ratio of 3:2, a diagonal measurement of 43 mm, it has been employed in countless photographic applications including single-lens reflex cameras, rangefinder cameras, mirrorless interchangeable-lens digital cameras, digital SLRs, point-and-shoot film cameras, disposable film cameras. The format originated with his introduction of the Leica camera in the 1920s, thus it is sometimes called the Leica Barnack format. The name 35 mm originates with the total width of the 135 film, the perforated cartridge film, the primary medium of the format prior to the invention of the full frame DSLR; the term 135 format remains in use. In digital photography, the format has come to be known as full frame, FF or FX, the latter invented as a trade mark of Nikon; the 35 mm format was sometimes called miniature format or small format, terms meant to distinguish it from medium format and large format.
The 35 mm format was conceived by Oskar Barnack by doubling the size of the 24×18 mm format used in cinema. The term 35 mm camera refers to a still photographic film camera which uses the 35 mm format on 135 film; such cameras have been produced by Leica, Argus, Canon, Olympus, Pentax, Carl Zeiss and numerous other companies. Some notable 35 mm camera systems are the original Leica, Leica M, Leica R, Nikon F, Argus C3, Canon FD, Canon EOS, Minolta OM, Pentax K-mount system, Minolta Maxxum/Dynax "A" mount system, the inter-compatible Contax and Yashica systems. Many digital image sensors approximate the dimensions of the 35 mm format, sometimes differing by fractions of a millimeter on one or both dimensions. Since 2007, Nikon has referred to their 35 mm format by the trade mark FX. Other makers of 35 mm format digital cameras, including Leica and Canon, refer to their 35 mm sensors as full frame. A true normal lens for 35 mm format would have a focal length of 43 mm, the diagonal measurement of the format.
However, lenses of 43 mm to 60 mm are considered normal lenses for the format, in mass production and popular use. Common focal lengths of lenses made for the format include 24, 28, 35, 50, 85, 105, 135 mm. Most a 50 mm lens is the one considered normal, any lens shorter than this is considered a wide angle lens and anything above is considered a telephoto lens. Wide angles shorter than 24 mm is called an extreme wide angle. Lenses above 50 mm but up to about 100 mm are called short telephoto or sometimes, as portrait telephotos, from 100 mm to about 200 mm are called medium telephotos, above 300 mm are called long telephotos. Many photographers think about angle of view in terms of 35 mm format lenses, due to the historic prevalence of the 35 mm format. For example, a photographer might associate a 50 mm focal length with a normal perspective, because a 50 mm lens produces that perspective on this format. With many smaller formats now common, lenses may be advertised or marked with their "35 mm equivalent" or "full-frame equivalent" focal length as a mnemonic.
This'equivalent' is computed by multiplying the true focal length of the lens by the ratio of the diagonal measurement of the native format to that of the 35 mm format. For example, a lens for APS-C format with a focal length of 40 mm, might be described as "60 mm." Although its true focal length remains 40 mm, its angle of view is equivalent to that of a 60 mm lens on a 35 mm format camera. Another example is the lens of the 2/3 inch format Fujifilm X10, marked with its true zoom range "7.1–28.4 mm" but has 35 mm-equivalent zoom control markings ranging from "28" to "112"
Canon FD lens mount
The Canon FD lens mount is a physical standard for connecting a photographic lens to a 35mm single-lens reflex camera body. The standard was developed by Canon of Japan and was introduced in March 1971 with the Canon F-1 camera, it served as the Canon SLR interchangeable lens mounting system until the 1987 introduction of the Canon EOS series cameras, which use the newer EF lens mount. The FD mount lingered through the release of the 1990 Canon T60, the last camera introduced in the FD system, the end of the Canon New F-1 product cycle in 1992; the FD mount replaced Canon's earlier FL mount. Though never explained by Canon, others have attempted to assign a meaning to the "FD" designation. One such attempt states that the "FD" notation stands for "Focal-plane shutter with Dual linkage for diaphragm control"; this is twice the previous lens series, which used the "FL" designation, said to mean "Focal-plane shutter, Linked mount."Over the 21-plus years of production, Canon introduced 134 different FD lenses ranging from 7.5mm through 1,200mm in seventeen different fixed focal lengths and nineteen different zoom ranges, one of the most, if not the most, extensive manual focus lens lines produced.
The Canon FD system enjoyed huge popularity in the 1970s and 1980s, when it established and grew a market share with professional photographers as well as having equipped over a million consumer users. Indeed, sales of the Canon AE-1 camera alone exceeded one million. Canon obsoleted. Thus, the FD mount system, with no provision for auto-focus, is now commercially obsolete, Canon FD cameras and lenses are available for low prices on the second-hand market; this makes the system attractive to 35mm film photographers who demand the highest optical quality, while not needing auto focus capability. FD lenses can be used on many mirrorless interchangeable-lens cameras with a suitable adapter, they are a popular alternative to modern lenses among some users. The FD lens mount is a breech-lock mount, a variation of the common triple-flanged bayonet attachment; the advantage of the breech-lock over the bayonet is that neither the contact surfaces between the body and lens, nor the signalling mechanisms, rotate against each other when the lens is mounted.
This prevents any mechanical wear, which could conceivably reduce the precise lens-to-film distance or introduce communication errors between lens and body. Canon's first iteration of the FD breech-lock, extended forward from the earlier R- and FL-series lenses, utilized a rotating mounting ring at the rear of the lens, its minor disadvantage was a somewhat slower lens change than a bayonet. There are three different versions of breech ring FD lenses: The first version had a chrome plated front barrel and a green "o" for auto exposure; the second version had a black front barrel and still had a green "o" for auto exposure. The third version had a black front barrel, a green "A" for auto exposure; these different versions are detailed below under variants. Second-generation FD lenses, first marketed in 1981 as New FD, are mounted like bayonet-mount lenses in that the photographer twists the entire lens body to mount and dismount, though the actual mating surfaces still remain fixed; this retained.
The letters SC or SSC to indicate the lens coating were no longer put on the lenses. Canon documents stated. Canon chose a bayonet-style mount for its EOS system's EF lenses, where there is no precision mechanical coupling. Like its FL predecessor, the FD mount system allowed automatic diaphragm function, but in addition, a new signal pin supported full-aperture metering. A second signal pin for the "auto" setting of the aperture dial, plus a linkage to allow the camera to set the degree of diaphragm opening, enabled integral auto-exposure; the first camera to utilize this was the 1971 Canon F-1. The Canon EF of 1973 had automatic exposure built-in, as did the popular Canon A-series cameras beginning in 1976. Thus, starting with the first FD lenses produced in late 1970, all FD lenses had the capability of supporting full-aperture metering and multiple Automatic Exposure modes using both shutter-preferred and aperture-preferred modes. Programmed AE was possible with no modifications to the lens mount, though at the time of its introduction Canon did not have an AE camera body in the FD line.
This was a design triumph for Canon that no other camera or lens maker was able to equal in 1970. Every other camera manufacturer had to make one or more alterations to its lens mount to enable full aperture metering, AE and or Programmed AE operation; the FD mount has no support for either electrical or mechanical lens-body communication required for autofocus, a primary reason for its retirement.. While Canon could have adapted its mount to support auto-focus, as did other manufacturers, the company instead chose to make a clean break with the past and design a new interface with support for electrical signaling and control; the earliest breech-lock Canon FD lenses are recognizable by a c
Single-lens reflex camera
A single-lens reflex camera is a camera that uses a mirror and prism system that permits the photographer to view through the lens and see what will be captured. With twin lens reflex and rangefinder cameras, the viewed image could be 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. Prior to the development of SLR, all cameras with viewfinders had two optical light paths: one path through the lens to the film, another path positioned above or to the side; 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 causes framing errors in close-up shots. Moreover, focusing the lens of a fast reflex camera when it is opened to wider apertures 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, align the image with the viewfinder; when the shutter is released, the mirror moves out of the light path, the light shines directly onto the film. The Canon Pellix, along with several special purpose high speed cameras, were an exception to the moving mirror system, wherein the mirror was a fixed beamsplitting pellicle. Focus can be adjusted manually automatically by an autofocus system; the viewfinder can include a matte focusing screen located just above the mirror system to diffuse the light. This permits accurate viewing and focusing 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 cameras with interchangeable parts, allowing customization, they have far less shutter lag, allowing photographs to be timed more precisely. The pixel resolution, contrast ratio, refresh rate, color gamut of an LCD preview screen cannot compete with the clarity and shadow detail of a direct-viewed optical SLR viewfinder. Large format SLR cameras were first marketed with the introduction of C. R. Smith's Monocular Duplex. SLRs for smaller exposure formats were launched in the 1920s by several camera makers; the first 35mm SLR available to the mass market, Leica's PLOOT reflex housing along with a 200mm f4.5 lens paired to a 35mm rangefinder camera body, debuted in 1935. The Soviet Спорт a 24mm by 36mm image size, was prototyped in 1934 and went to market in 1937. K. Nüchterlein's Kine Exakta was the first integrated 35mm SLR to enter the market.
Additional Exakta models, all with waist-level finders, were produced up to and during World War II. Another ancestor of the modern SLR camera was the Swiss-made Alpa, innovative, influenced the Japanese cameras; the first eye-level SLR viewfinder was patented in Hungary on August 23, 1943 by Jenő Dulovits, who 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 the world's first SLR with an instant-return mirror; the first commercially produced SLR that employed a roof pentaprism was the Italian Rectaflex 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 developed the Asahiflex and in 1954, the Asahiflex IIB.
In 1957, the Asahi Pentax combined the right-hand thumb wind lever. Nikon and Yashica introduced their first SLRs in 1959; as a small matter of history, the first 35 mm camera 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 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 photocells; the cells were either located in the pentaprism housing, where they metered light transmitted through the focusing screen. Pentax was the first manufacturer to show an early prototype 35 mm behind-the-lens metering SLR camera, named the Pentax Spotmatic; the camera was shown at the 1960 photokina show. However, the first