Hello and good evening, Background: Let's turn back the clock to 1956 post-war Germany, when most of England and Continental Europe were rebuilding after the devastation of the Second World War. The destruction of the war caused many companies to divide into smaller subcompanies and others to merge. There was great respect for the engineering innovation that came out of Dresden—before the war the world's first 35 mm single-reflex cameras such as the Kine Exakta, and the first miniature camera with good picture quality were developed there. The western business was restarted in Oberkochen (in southwestern Germany) as Opton Optische Werke Oberkochen GmbH in 1946, which became Zeiss-Opton Optische Werke Oberkochen GmbH in 1947, but was soon renamed to Carl Zeiss. West German Zeiss products were labelled Opton for sale in the Eastern bloc, while East German Zeiss products were labelled "Zeiss Jena" or simply "Jena" for sale in Western countries. History: Hubert Nerwin, the designer of the pre-war Contax II and Contax III brought out the first Contaflex SLR which was introduced in 1953 as one of the earliest 35mm SLR cameras equipped with a leaf shutter, but with a fixed lens. The Mecaflex was presented at in 1951 and launched two years later with a leaf shutter behind the removable lens, while the Hasselblad 500C Photokina of 1957 has a leaf shutter in its interchangeable lens. This design, using a leaf shutter in an SLR, involves a complex sequence of events when the shutter is released, more looked upon as a challenge than a drawback at Zeiss Ikon, but no Contaflex model ever got a rapid return mirror. The advantages are low manufacturing costs, compactness and flash synchronization at all shutter speeds. However, only a very limited range of interchangeable lenses became available. For the models I and II, having a fixed lens, only three add-on converters were offered using a slide-on adapter, but from models III and IV onwards interchangeable lenses from 35mm to 115mm focal length were provided; at the time regarded as quite sufficient, as most would only be used with the standard lens anyway. Three years later, during 1956, the Kodak Retina Reflex was launched, followed by the Voigtländer Bessamatic and the Ultramatic. The market soon flourished with leaf-shuttered SLR cameras. These mechanical complex cameras required precision assembly and high quality materials. More often than not many camera makes suffered from reliability issues, while the few better ones performed well, selling in quantity. Contaflex III and Contaflex IV: The Contaflex III, launched in 1956, was the same as the I, but equipped with a Zeiss Tessar 50mm f:2.8 with helical focusing. The front element of the lens was removable and could be replaced by supplementary lenses. The Contaflex IV, introduced the same year, was the same camera with the uncoupled meter inherited from the Contaflex II. I own a Contaflex IV with lens hood and leather case. This was a fairly expensive camera at the time when new, but it's the fantastic Carl Zeiss 50mm f2.8 Tessar lens with removable front element and the built quality of solid brass and chrome along with the Synchro-Compur Leaf Shutter from B to 1/500 sec. it's what makes this camera a treat to use.