Originally posted by Duowing Helios 44-2 Mounting off with Spotmatic F?
Is this an M39 (Zenit) Helios 44-2 or M42? If M39, the problem may be with the adapter.
M42 pre-set Biotars have clearance problems on some M42 bodies due to having both an ample rear and a shield around rear element. The Helios 44-2, may share that characteristic. Since the SP F has a more constrained mirror box than earlier Spotmatic models, this may be reason for concern.
I suggest visually checking for clearance with shutter on B and the film door open:
- Adjust focus to closest distance and begin threading the lens into the mount, say two turns.
- Continue threading the lens on while looking through from the back (film door open). This is most easily done with the camera on tripod.
- As it comes to close to seating on the flange note check for points of possible interference.
- Once seated to the mount flange, focus slowly to infinity while monitoring the position of the rear element and any shields.
If there is any interference, it should be evident.
Steve