In an article which appeared in Popular Photography, August 1983, Ansel said, “I have worked with Contax I, II, III and the Contarex Professional…” I have not found any other references to the Contax III; however, I have seen a photo online of a display with a Contax III purported to be his camera.
The camera shown here is a late 1930s Contax III, with an early 1930s 50mm Zeiss Sonar lens.
The Contax III was basically a Contax II with a builtin light-meter. These were a significant 1936 improvement over original Contax of 1932. The shutter was more reliable, the speed controls were all incorporated into one knob, and the rangefinder and viewfinder windows were combined. The film loading was also much simpler than on a Barnack Leica of that era.
Despite the extra feature, these don’t seem to have been as popular as the II, especially with the press. However, since Contax cameras were a very expensive investment, it is likely that wealthy amateurs were not put-off my the additional cost. There are many of these available on the used market.