The Asahiflex was a 35 mm single-lens reflex camera built by the Asahi Optical Corporation (later to become Pentax ).
32-530: Asahi Optical introduced its first 35 mm camera in 1952. Unlike the majority of Japanese camera manufacturers of the time, Asahi made a conscious decision not to produce a mere German rangefinder copy, a relatively simple task. Instead, Asahi decided to copy the Praktiflex , a 1939 design, made in the German Democratic Republic. Asahi's designers (Nobuyuki Yoshida and Ryohei Suzuki) were convinced of
64-608: A direct optical viewfinder for eye-level use. Like the Praktiflex the Asahiflex I did not have a returning mirror (which means the mirror will only be back to its initial position to redirect light to the viewfinder for composing and range finding work after the operators had wound the film) and shutter speeds from 1/20 to 1/500 and B. The camera used the M37 screw mount. The Asahiflex I went through some minor modifications for flash use, resulting in
96-639: A more rigid, stable and flatter plane compared to plastic films. Beginning in the 1970s, high-contrast, fine grain emulsions coated on thicker plastic films manufactured by Kodak, Ilford and DuPont replaced glass plates. These films have largely been replaced by digital imaging technologies. The sensitivity of certain types of photographic plates to ionizing radiation (usually X-rays ) is also useful in medical imaging and material science applications, although they have been largely replaced with reusable and computer readable image plate detectors and other types of X-ray detectors . The earliest flexible films of
128-510: A photographic plate. Glass-backed plates, rather than film, were generally used in astronomy because they do not shrink or deform noticeably in the development process or under environmental changes. Several important applications of astrophotography , including astronomical spectroscopy and astrometry , continued using plates until digital imaging improved to the point where it could outmatch photographic results. Kodak and other manufacturers discontinued production of most kinds of plates as
160-602: A place to archive them. APDA is dedicated to housing and cataloging unwanted plates, with the goal to eventually catalog the plates and create a database of images that can be accessed via the Internet by the global community of scientists, researchers, and students. APDA now has a collection of more than 404,000 photographic images from over 40 observatories that are housed in a secure building with environmental control. The facility possesses several plate scanners, including two high-precision ones, GAMMA I and GAMMA II, built for NASA and
192-431: A small selection of standard lenses became available, e.g.: Photographic plate Photographic plates preceded photographic film as a capture medium in photography. The light-sensitive emulsion of silver salts was coated on a glass plate , typically thinner than common window glass. They were heavily used in the late 19th century and declined through the 20th. They were still used in some communities until
224-547: Is a particular need in astronomy, where changes often occur slowly and the plates represent irreplaceable records of the sky and astronomical objects that extend back over 100 years. The method of digitization of astronomical plates enables free and easy access to those unique astronomical data and it is one of the most popular approaches to preserve them. This approach was applied at the Baldone Astrophysical Observatory where about 22,000 glass and film plates of
256-460: Is extremely complicated by comparison, and although it provides the same functions, is quite differently built. The Praktiflex has a 40mm screw lens mount, while the later Praktica models, after World War II when the factory was part of the VEB Pentacon , uses the 42mm screw mount . The Praktiflex has one feature inherited from the large format plate SLR cameras that otherwise was unsolved in
288-608: The Holtermann Collection . These purportedly were the largest glass negatives discovered at that time. These images were taken in 1875 by Charles Bayliss and formed the "Shore Tower" panorama of Sydney Harbour. Albumen contact prints made from these negatives are in the holdings of the Holtermann Collection, the negatives are listed among the current holdings of the Collection. Preservation of photographic plates
320-819: The Schmidt Telescope were scanned and cataloged. Another example of an astronomical plate archive is the Astronomical Photographic Data Archive (APDA) at the Pisgah Astronomical Research Institute (PARI). APDA was created in response to recommendations of a group of international scientists who gathered in 2007 to discuss how to best preserve astronomical plates (see the Osborn and Robbins reference listed under Further reading). The discussions revealed that some observatories no longer could maintain their plate collections and needed
352-541: The 1950s, the follow-up POSS-II survey of the 1990s, and the UK Schmidt Telescope survey of southern declinations . A number of observatories , including Harvard College and Sonneberg , maintain large archives of photographic plates, which are used primarily for historical research on variable stars . Many solar system objects were discovered by using photographic plates, superseding earlier visual methods. Discovery of minor planets using photographic plates
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#1732869184833384-519: The 1950s. The Praktiflex 35mm SLR film camera was launched in 1939 by the Kamera-Werkstätten AG, Dresden -Niedersedlitz. Despite being quite crude, the design constitutes the pattern along which virtually every subsequent 35mm SLR camera is built, regardless of place of origin. The highly regarded 35mm SLR Kine Exakta , by Ihagee in Dresden, that preceded it by some three years,
416-545: The 1970s, and by one in Bradford called the Belle Vue Studio that closed in 1975. They were in wide use by the professional astronomical community as late as the 1990s. Workshops on the use of glass plate photography as an alternative medium or for artistic use are still being conducted. Many famous astronomical surveys were taken using photographic plates, including the first Palomar Observatory Sky Survey ( POSS ) of
448-502: The 35mm SLR cameras until 1954; the instant return mirror is lifted by the power of the finger depressing the shutter release, and it returns when the finger pressure is released. The button, with a rather long travel, is placed at the right-hand camera top plate. The slanted script is embossed in the name plate in front of the collapsible waist-level finder . The principal designers were presumably Benno Thorsch and Charles A. Noble . Several finishes and improvements were implemented in
480-562: The IA. Note: Both in the Praktiflex and the Asahiflex I the reflex mirror returned to its original position after taking your finger from the shutter release button. The Asahiflex IIB was released in 1954. With the IIB, a key advance was made, the quick-return mirror. It was the world's first SLR camera with an instant return mirror . The problem of mirror black-out was one of the main problems with prior SLR designs, greatly reducing usability and leading to
512-601: The Space Telescope Science Institute (STScI) and used by a team under the leadership of the late Barry Lasker to develop the Guide Star Catalog and Digitized Sky Survey that are used to guide and direct the Hubble Space Telescope . APDA's networked storage system can store and analyze more than 100 terabytes of data. A historical collection of photographic plates from Mt. Wilson observatory
544-574: The camera is wound-on for the next frame. The name is embossed in gothic letters, otherwise the external body features is quite similar to those of the original model. This version is known as the Praktiflex II by collectors. The lens mount is at first the 40mm screw, but later cameras have the new 42mm lens mount, first used on the Contax S and the Praktica of 1949, since production lasted until 1951. Only
576-409: The course of the production period of the Praktiflex, which was from 1939 to 1949, but probably disrupted at times between 1941 and 1946. Some variations concern the colour schemes while others the mechanical details: In 1947 an improved Praktiflex version was launched with a new internal mechanism and a shutter release at the front that releases a spring-loaded mirror, which does not return until
608-604: The factory to Niedersedlitz on the outskirts of Dresden, while Benno Thorsch in Detroit ran the acquired photo finishing business that was one of the largest in the USA. The new Kamera-Werkstätten AG, Niedersedlitz prospered, and in 1939 launched the 35mm SLR Praktiflex camera. The concept proved successful, and through continuous development, the Praktica name became one of the most popular 35mm SLR brands for several decades, beginning in
640-608: The greater popularity of the rangefinder. With the IIB there emerged the first practical quick-return mirror, a vital innovation and one which was quickly adopted by other manufacturers. With the final model in the series, the IIA, the Asahiflex gained slow speeds from 1/25th of a second to 1/2 of a second. 2. "Asahiflex I - Pentax M37 Screwmount Slrs - Pentax Camera Reviews And Specifications". Pentaxforums.Com , 2022, https://www.pentaxforums.com/camerareviews/asahiflex-a.html. Praktiflex Kamera-Werkstätten Guthe & Thorsch (K.W.)
672-453: The inherent superiority of the SLR and so proceeded along these lines. This effort resulted in the Asahiflex I, which was also the first Japanese 35 mm SLR. Note: According to company information from Asahi Optical Co., however, the Asahiflex I is based on Mr. Matsumoto’s Kochmann Reflex-Korelle, a pre-war 6x6 roll film camera. The Asahiflex I had a non-interchangeable waist-level viewfinder, with
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#1732869184833704-487: The intensity of the rays. Development of particle detection optimised nuclear emulsions in the 1930s and 1940s, first in physics laboratories, then by commercial manufacturers, enabled the discovery and measurement of both the pi-meson and K-meson , in 1947 and 1949, initiating a flood of new particle discoveries in the second half of the 20th century. Photographic emulsions were originally coated on thin glass plates for imaging with electron microscopes , which provided
736-400: The largest CCD formats (e.g., 8192 × 8192 pixels) still do not have the detecting area and resolution of most photographic plates, which has forced modern survey cameras to use large CCD arrays to obtain the same coverage. The manufacture of photographic plates has been discontinued by Kodak, Agfa and other widely known traditional makers. Eastern European sources have subsequently catered to
768-506: The late 1880s were sold for amateur use in medium-format cameras. The plastic was not of very high optical quality and tended to curl and otherwise not provide as desirably flat a support surface as a sheet of glass. Initially, a transparent plastic base was more expensive to produce than glass. Quality was eventually improved, manufacturing costs came down, and most amateurs gladly abandoned plates for films. After large-format high quality cut films for professional photographers were introduced in
800-507: The late 1910s, the use of plates for ordinary photography of any kind became increasingly rare. The persistent use of plates in astronomical and other scientific applications started to decline in the early 1980s as they were gradually replaced by charge-coupled devices (CCDs), which also provide outstanding dimensional stability. CCD cameras have several advantages over glass plates, including high efficiency, linear light response, and simplified image acquisition and processing . However, even
832-427: The late 20th century. Glass plates were far superior to film for research-quality imaging because they were stable and less likely to bend or distort, especially in large-format frames for wide-field imaging. Early plates used the wet collodion process . The wet plate process was replaced late in the 19th century by gelatin dry plates . A view camera nicknamed "The Mammoth" weighing 1,400 pounds (640 kg)
864-426: The market for them dwindled between 1980 and 2000, terminating most remaining astronomical use, including for sky surveys. Photographic plates were also an important tool in early high-energy physics , as they are blackened by ionizing radiation . Ernest Rutherford was one of the first to study the absorption, in various materials, of the rays produced in radioactive decay , by using photographic plates to measure
896-604: The minimal remaining demand, practically all of it for use in holography , which requires a recording medium with a large surface area and a submicroscopic level of resolution that currently (2014) available electronic image sensors cannot provide. In the realm of traditional photography, a small number of historical process enthusiasts make their own wet or dry plates from raw materials and use them in vintage large-format cameras. Several institutions have established archives to preserve photographic plates and prevent their valuable historical information from being lost. The emulsion on
928-601: The plate can deteriorate. In addition, the glass plate medium is fragile and prone to cracking if not stored correctly. The United States Library of Congress has a large collection of both wet and dry plate photographic negatives, dating from 1855 through 1900, over 7,500 of which have been digitized from the period 1861 to 1865. The George Eastman Museum holds an extensive collection of photographic plates. In 1955, wet plate negatives measuring 4 feet 6 inches (1.37 m) × 3 feet 2 inches (0.97 m) were reported to have been discovered in 1951 as part of
960-621: Was built by George R. Lawrence in 1899, specifically to photograph "The Alton Limited " train owned by the Chicago & Alton Railway . It took photographs on glass plates measuring 8 feet (2.4 m) × 4.5 feet (1.4 m). Glass plate photographic material largely faded from the consumer market in the early years of the 20th century, as more convenient and less fragile films were increasingly adopted. However, photographic plates were reportedly still being used by one photography business in London until
992-640: Was established 1919 in Dresden by Paul Guthe and Benno Thorsch , starting out manufacturing the Patent Etui plate camera . Ten years later came the roll film TLR Pilot Reflex and in 1936, the 6×6 SLR Pilot range. By that time, Benno Thorsch, the surviving partner from 1919, decided to immigrate to the United States and arranged with the US citizen Charles Noble to swap enterprises. Noble came to Germany and moved
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1024-460: Was pioneered by Max Wolf beginning with his discovery of 323 Brucia in 1891. The first natural satellite discovered using photographic plates was Phoebe in 1898. Pluto was discovered using photographic plates in a blink comparator ; its moon Charon was discovered 48 years later in 1978 by U.S. Naval Observatory astronomer James W. Christy by carefully examining a bulge in Pluto's image on
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