One of the most desirable lenses for the Contax, at least from a collectors standpoint is the 75/1.5 Biotar. it was brought to the market at an inopportune time, as the war was really heating up in 1940. A small batch were built for the Contax that year, estimated at 100 units. Production was resumed in East Germany after the war, most likely all in aluminum barrel. The design was also then produced more widely in Exakta and 42mm thread mounts. Production of the postwar version is 800 lenses in Contax mount.