Topcon

is a Japanese manufacturer of optical equipment for ophthalmology and surveying.

is a Japanese manufacturer of optical equipment for ophthalmology and surveying. ==History== ==Cameras== Tokyo Kogaku produced cameras, beginning with a 6×4.5 cm medium format model, Lord in 1937. A 127 film camera followed the next year. The Primoflex I twin-lens reflex camera came out in 1951. The Topcon 35A was unveiled in 1953. In 1960 the company produced a 6x9 press camera on order from the Tokyo Metropolitan Police Department. It initially used a Mamiya lens; civilian models became available with Topcon lenses. ===35mm SLR cameras=== The third 35mm SLR camera released in Japan was Tokyo Kogaku's Topcon R (1957¹), which features a "semi-automatic" aperture: the photographer composes the image, selects an aperture, presses a lever to charge a spring, and then presses the shutter release, which also releases the spring to stop down the aperture to the selection as the focal-plane shutter is opened. Because of this arrangement, the Auto-Topcor lenses have a triangular protrusion which overlaps the shutter release mounted on the front of the camera body. Topcon cameras put the shutter release under the photographer's right index finger, making the Topcor lenses incompatible with Exakta cameras, despite sharing the same mechanical bayonet mount. In the United States, the Charles Beseler Company sold the Topcon R as the Beseler Topcon B. Compared to its contemporary competitors, the Topcon R used a quick-return mirror, which allowed the photographer to recompose immediately after taking a picture, although this advantage was mostly lost as the lens remained stopped down, only returning to full aperture when the presetting lever was charged. Tokyo Kogaku introduced the Topcon PR in 1959, which was the start of a lower-priced in-lens leaf shutter SLR line with a fixed Tessar-derived 50 mm lens; shutter speeds range from 1 to  sec. Two front-mounted converter lenses were available, with a composite system focal lengths of 37 mm and 94 mm . It was succeeded by the PR II (1960), which had mostly minor cosmetic changes but added automatic diaphragm operation, and was accompanied by a third conversion lens with a focal length of 85 mm. Beseler imported this camera into the US as the Beseler Topcon A (although not marked as such), and it also was sold by DeJUR as the Dekon-SR. Later that year, the Topcon Wink Mirror was released, which incorporated a faster double Gauss lens, although still fixed, and a quick-return mirror. A new set of converter lenses were made available, for 35 mm and 80 mm . Also in 1960, Tokyo Kogaku released the Topcon R II or Automatic Topcon R, which added an automatic diaphragm function to the focal plane SLR line; Beseler sold this as the Beseler Topcon C. 1961 followed with the Wink Mirror E, which adds a selenium photocell light meter to the front of the Wink, but was otherwise unchanged; the lens incorporated a material that acts as an UV filter and so was renamed UV Topcor. The Wink Mirror E was similarly imported into the United States as the Beseler Topconette. In addition, the Topcon R III was introduced in 1961, partly in response to the Nikon F and Canon Canonflex (both 1959), although it was little changed compared with the R II: the most prominent difference is the presence of a front-mounted cold shoe just above the shutter release on the R III for a shutter speed-linked selenium meter. The R II was accompanied by a line of F.Auto-Topcor lenses, which dropped the triangular projection and used black-finished aluminum barrels. The focal plane Topcon R SLRs soon were followed by the short-lived Topcon RS (1962), which traded the selenium meter for one with a photoresistor. Tokyo Kogaku updated its leaf-shutter SLR line with the Wink Mirror S in 1963, which added an interchangeable lens mount and a shutter-priority autoexposure mode. Lenses with the UV Topcor mount do not have an aperture control, which remained on the body. In Europe, the Wink Mirror S was sold as the Porst Reflex S. 1963 also brought the Topcon RE Super, which improved on the RS with full-aperture, through-the-lens metering; this was imported into the United States as the Beseler Topcon Super D and the UK/Australia/New Zealand as the Hanimex Topcon RE Super. Numerous minor changes were implemented while the RE Super was being sold. In addition, the Exakta-mount lens line was updated again with the RE.Auto-Topcor designation, carrying distinctive silver barrels. In about 1965, the US Navy tested cameras from several Japanese and German manufacturers (including the Nikon F). The Super D was the winner of this competition, and was used exclusively by the Navy until 1977¹. In 1964, another upgrade to the leaf-shutter line, the Topcon Uni, made it the world's first SLR with through-the-lens metering and shutter-priority autoexposure; in the US it was sold as the Beseler Auto 100. Beseler touted the camera's "Meter-inside-the-Mirror". The Topcon RE-2 was introduced in 1965 aimed at the mid-range market, switching the horizontally-running focal plane shutter for a vertical Copal unit; this is immediately distinguishable through the switched positions of the shutter speed selector (now on the front of the body) and the shutter release (on the top deck). As before, the RE-2 was sold under rebadged version as the Beseler Topcon D-1 and Hanimex Topcon RE-2. By 1969, the last of the 35mm leaf-shutter SLRs was released, the Topcon Unirex, sold in the US as the Beseler Topcon Unirex; its primary upgrade was the ability to switch between spot and average metering patterns, though a 1972¹ export-only model, the Unirex EE, removed that function. The Topcon Super DM succeeded the RE Super in 1973; the primary improvement was the ability to attach a winder and later motor drive, and it was sold until Tokyo Kogaku withdrew from the photographic market in 1981¹, again with numerous minor changes throughout its production. Also in 1974, the production of the IC-1 AUTO SLR started; "IC" means "Integrated Circuit", used for aperture control. The IC-1 uses the UV mount and has a body shape similar to the Unirex, but incorporates a focal plane shutter instead while maintaining the capability of shutter-priority autoexposure. The Hi Topcor lenses released alongside the IC-1 may not be fully compatible with earlier cameras. The final cameras with an Exakta-based mount were released in 1977 and 1978, the Topcon RE200 and RE300, respectively, which also were sold under the Exakta brand as the EDX2 and EDX3. The last SLR released by Tokyo Optical was the Topcon RM300, which uses the Pentax K-mount and rebadged with numerous versions including Exakta CX5, KE 4 and KE 5; Rony RS1; Carena KSM 1; Quantaray D2-RZ. A successor was developed, the K-mount Topcon AM-1, but was not released before Tokyo Optical withdrew from the market in 1981; Cima Optical, to which Tokyo Optical previously had subcontracted lens assembly, purchased the design and released it as the Cimko LS-1 in 1983. ===Lenses for 35mm SLRs=== Tokyo Optical produced both fixed and interchangeable lens SLR cameras; the interchangeable lenses were split into two separate types, one for cameras with focal plane shutters (using an Exakta bayonet mount) and another for cameras with leaf shutters (using the UV mount). The fixed-lens SLRs had leaf shutters; the earliest lenses fitted to the PR and PR II were 50 mm four element / three group designs derived from the venerable Tessar. These were succeeded by the 48 mm double Gauss lens fitted to the Wink Mirror and Wink Mirror E. Focal plane shutter SLRs use an Exakta mount; the earliest of these lenses were introduced with the Topcon R in 1957: 35 mm , 58 mm , 100 mm , and 135 mm , all labeled as Auto-Topcor with the triangular projection overlapping the front-mounted shutter release. These early Auto-Topcor lenses included the aperture charging lever; later production lenses and those sent to the export market omit the charging lever, as pressure on the lens button would open the aperture and close it down to the preset. With the R II, the triangular flange was omitted from the same four lenses, now labeled as F Auto-Topcor with black-finished bodies, a rubber inset for the focusing ring, and a clear plastic window covering the distance scale. The F series added the automatic diaphragm action lever, at approximately 3 o'clock on the lens flange, which held the aperture open during composition and focusing, then when the shutter was released, stopped the diaphragm to its preset value. The RE Auto-Topcor series, distinguished by their silver-colored bodies and black rubber inset focusing rings, added an aperture keying pin to allow the body to read the aperture selected on the lens. This pin rides in a arc-shaped groove from approximately 11 o'clock to 1 o'clock on the lens flange. Interchangeable lenses for leaf-shutter SLRs are labeled UV Topcor or Hi Topcor. Adaptors exist to mount UV-mount lenses on R-mount bodies and vice versa; however, the aperture control for UV/Hi Topcor lenses is mounted on the body, so the UV lens to R-mount body adapter includes an iris control ring. In addition, the leaf-shutter SLR lenses are relatively slow compared to the Exakta/R-mount equivalent focal lengths. ==Gallery== ==References== ==External links==

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