Originally posted by Jean Poitiers Gelios 103 ...
Yes...that is the lens. It is an Arsenal Helios-103 53/1.8 (aka Gelios) in Contax/Kiev mount.
I am so unfair. This one would only be obvious to people who are familiar with a wide range of interchangeable lens rangefinder cameras. Familiarity with FSU stuff helps too. The camera is my new Bessa R3M, which uses the Leica M mount. The lens was only made in Contax/Kiev mount and was originally sold as kit with Kiev 4M and 4AM bodies.
What is unusual is that the Helios is mounted to the Bessa. The two systems generally do not mix, for multiple reasons. People who are familiar with either system will scratch their heads at the appearance of what looks to be a Contax mount complete with both inner and outer bayonet on a Leica M mount camera. That mount face belongs to the fairly unusual Amedeo adapter which provides full rangefinder coupling for both internal and external bayonet Contax-mount lenses.
Steve