Code: ATOOH,LIGOO, AZOOB/LUDOO, ARHOO/LEYOO, LEHEK, AMXOO/LOOBT
Period; 1938 - 1946; serial numbers: 240001 - 355000: total about 32000
Viewfinder and rangefinder eyepieces closer together.
In 1936 the Zeiss Company introduced the first serious competition for the Leica rangefinder camera. There is a time lag of a decade between the first Leica camera and the Zeiss Contax. This long delay indicates that decision making and preparation for design and manufacture moved in a much more leisurely pace than in current days where competition is within at most a year and production cycles are down to two-three years. The Contax had a vertically running focal plane shutter with a string of metal slats as curtains and most important a finder with integrated viewfinder/rangefinder for easy viewing and focusing simultaneously. This feature the Leica lacked with its two separate eyepieces and the introduction of the IIIb in 1938 was a reaction to the Contax camera. The IIIb is essentially a IIIa with the two eyepieces very close together so that you could view and focus with just a slight movement of the eye from one to the other eyepiece. The IIIb stayed in the catalogues from 1938 to 1940, but some authors assume that the IIIb was also made during WW2 for military orders.