Coldkennels
Barnack-toting Brit.
You should be able to mount a 50mm lens at any point - it clips into the internal bayonet, and as there's no focusing helical in the lens itself, it's pretty much position-agnostic when you mount it. It's only external mount lenses that need to be set to infinity (with the body set to infinity, too) to make sure it connects to the rangefinder correctly. Even then they might need a bit of a "wiggle" after mounting to make sure everything's seated properly.I a, using the the '36 CZJ %cm f/2.0 that came with the camera. But I understand (?) that if you mount the lens when the focus is not at infinity you are screwed. The lens is good. And for $200 I got a '37 CZJ 5cm f/1.5, coated. The III came along for free.
@Miles. makes a valid point, though - if your f/2 Sonnar is a collapsible one, it has to be fully extended and locked. That's the only way a 50mm Contax lens can go wrong... assuming the RF and lens are calibrated correctly, of course.

