Quote Originally Posted by Tony-S View Post
Minolta.

Good morning, Tony;

It may be that any adapter to go from an M-42 lens to the Minolta SR mount will require some glass in the optical path to achieve focus at infinity. Both of the Minolta Adapters for the M-42/Contax/Pentax/UTM lenses and the Leica M-39 lenses are simple machined adapter rings without any glass, and specifically state in the instructions that they are for use in close-up work only, and will not achieve focus at infinity.

The lens registration distance for the Minolta Maxxum/Dynax AF lens mount and the later Sony DSLR AF lens mount is longer than the Minolta SR lens mount, so the same comments will apply there also.