After the Second World War, a few Contax cameras were produced at the original Dresden factory, and some were assembled at the Carl Zeiss optical works at Jena, before production was transferred to Kiev in Ukraine. During the war years, the chief designer, Hubert Nerwin, tried to convert the Contax into a single-lens reflex camera but was hindered by the presence of the upper roller of the vertical focal-plane shutter. The postwar design chief Wilhelm Winzenberg started with a clean slate, which became the Contax S (Spiegelreflex), even though the "S" was not marked on the camera.