A Prontor-Compur connection (also known as a PC connector, PC terminal, or PC socket) is a standard 3.5 mm (1/8") electrical connector (as defined in ISO 519) used in photography to synchronize the shutter to the flash.
"Prontor" has its origins in the Italian word "pronto", meaning ready (and was a leaf shutter made by Alfred Gauthier). "Compur" is derived from the word "compound" (the "Compound" was a long-lived series of leaf shutters made by Friedrich Deckel).
The term is derived from brands of widely marketed photographic leaf shutters manufactured from the early 1950s by two distinct, but now defunct German companies. Gauthier (which made the Prontor-S and Prontor SV models, amongst others) and Deckel (the Synchro-Compur model, successor to the Compound model).
Both companies' brands, Prontor (from 1953) and Compur (from 1951), shared a common 1/8"-inch coaxial connector for shutter/flash synchronization. This convergence of design is not as coincidental as it might first appear, owing to the fact that the Zeiss organisation held a significant shareholding in both of these companies prior to the introduction of the shared connector. By the 1950s, Gauthier were manufacturing up to 10,000 Prontor shutters daily.
The Gauthier company's essence lives on as Prontor GmbH, which is a wholly owned subsidiary of VTC Industrieholding GmbH. The Deckel company went bankrupt in 1994.
In a camera, flash synchronization is defined as synchronizing the firing of a photographic flash with the opening of the shutter admitting light to photographic film or electronic image sensor. It is often shortened to flash sync or flash synch.
In cameras with mechanical (clockwork) shutters synchronization is supported by an electrical contact within the shutter mechanism, which closes the circuit at the appropriate moment in the shutter opening process. In electronic digital cameras, the mechanism is usually a programmable electronic timing circuit, which may, in some cameras, take input from a mechanical shutter contact. The flash is connected electrically to the camera either by a cable with a standardised coaxial PC (for Prontor/Compur) 3.5 mm (1/8") connector (as defined in ISO 519), or via contacts in an accessory mount (hot shoe) bracket.
Faster shutter speeds are often better when there is significant ambient illumination, and flash is used to flash-fill subjects that are backlit without motion blur, or to increase depth of field by using a small aperture. In another creative use, the photographer of a moving subject may deliberately combine a slow shutter speed with flash exposure in order to record motion blur of the ambient-lit regions of the image superimposed on the flash-lit regions.Kodak Retina Reflex
The Kodak Retina Reflex was a series of four single-lens reflex cameras made by Kodak, continuing the brand Kodak Retina.List of abbreviations in photography
During most of the 20th century photography depended mainly upon the photochemical technology of silver halide emulsions on glass plates or roll film. Early in the 21st century this technology was displaced by the electronic technology of digital cameras. The development of digital image sensors, microprocessors, memory cards, miniaturised devices and image editing software enabled these cameras to offer their users a much wider range of operating options than was possible with the older silver halide technology. This has led to a proliferation of new abbreviations, acronyms and initialisms. The commonest of these are listed below. Some are used in related fields of optics and electronics but many are specific to digital photography.Mecaflex
The Mecaflex is a 35mm SLR camera for 50 exposures of 24 × 24 mm. It was presented at the photokina in Cologne in 1951, and launched commercially about two years later. The design is by Heinz Kilfitt, who is also known for designing the original Robot camera and the Kowa Six.The camera is equipped with the newly developed Prontor-Compur (PC) reflex shutter, which would pave the way for reputable camera designs such as the 1953 Contaflex, the 1956 Retina Reflex, the 1957 Hasselblad 500, and the 1959 Voigtländer Bessamatic. However, it does not have the built-in eye-level pentaprism finder, which was first seen on 35mm SLR cameras in 1949. Instead, it has a waist-level finder with a central split-image rangefinder complemented by large full frame magnifier incorporating a central loupe that covers the rangefinder central area.Olympus Trip 35
The Trip 35 is a 35mm compact camera, manufactured by Olympus. It was introduced in 1967 and discontinued, after a lengthy production run, in 1984. The Trip name was a reference to its intended market – people who wanted a compact, functional camera for holidays. During the 1970s it was the subject of an advertising campaign that featured popular British photographer David Bailey. Over ten million units were sold.The Trip 35 was a point and shoot model with a 40mm f2.8 lens, solar-powered selenium light meter, and just two shutter speeds. In 'A' mode, the camera operated as a Program automatic, choosing either 1/40th sec or 1/200th sec. The camera could also sync with flash, and had a range of aperture settings, from f2.8 to f22. In flash sync mode the shutter was set at 1/40. Apart from a simple four-position zone focus system, and an ISO setting from 25–400, the camera had no other photographic controls. The camera had a Prontor-Compur sync connector and a hot shoe. Its lens was a coated Zuiko 40mm f/2.8, with four elements in three groups.
The camera had an ISO range of "only" 25–400, but this was acceptable, as films faster than 400 were uncommon and not of high image quality. 25 speed allowed the use of Kodachrome, while 400 speed allowed use of Tri-X and similar fast materials under low light.
Earlier models, from the first few years of production, had a maximum ISO speed of 200.
The four-element Tessar lens, still impressive today, gave high-quality images. If used with modern film emulsions, the results can be very good.
The use of a selenium photocell to select the shutter speeds and aperture let novices use the camera as a "point & shoot", with good results obtained most of the time. And no battery was needed to power the camera, an important consideration when travelling where batteries might not be available.
The lack of more than two shutter speeds was not a problem. At 1/200 and f:22 with 400-speed film, the camera could deliver correct exposure in full sunlight, while at 1/40 and f:2.8, correct exposure could be obtained under bright fluorescent light, without a flash.
The aperture could also be adjusted to cope with sunny/dull conditions etc., so again this allowed for better results, but in low light conditions, with perhaps a smallish aperture (for long depth of field), the camera would probably set itself to the lower speed of 1/40th, so camera shake was a possibility if higher-speed film was not used.
ISO standards by standard number