contax 645 adapter to fit mamiya 645?

[Evanjoe610]

Bo Ming,
Thank you for the update regarding the NAM-1 conversion. Would it be safe to assume that all of the Contax 645 lenses will work without any problems on all of the Canon EOS DLSR? Any problem using it on thew Rebel T2i?

Evan

The original question of whether it was possible to adapt a Contax 645 lens to Mamiya 645 mount.

The Contax 645 mount is entirely electronic but the Mamiya 645 AF mount is half electronic and half mechanical. The aperture diaphragm of Mamiya 645 AF is controlled electronically but there is a mechanical AF shaft to drive AF. Manual focus Mamiya 645 lenses will fit an autofocus Mamiya camera body but needs to use stopped-down metering.

Electronically, if you don't care about AF, there is theoretically some way to interface the aperture control. However mechanical is another story. The Contax 645 mount has a much bigger diameter than Mamiya 645 so it is impossible for the former's bayonet to fit inside the latter's mount throat. It is physically impossible without losing infinity focus.

As it now is, a Contax 645 lens can only be adapted using a converted NAM-1 adapter on a Canon camera body, retaining full AF and aperture diaphragm control.