Quote Originally Posted by Yashinoff View Post
I recently disassembled an Edixa SLR to reglue a shutter strap that came loose. This required removing the mirror box and consequentially the lens mount from the camera body. The mount had a number of shims behind it to align it properly with the film plane. I want to know what the proper procedure is for checking the alignment of the mount with the film plane. I assume this is something that cannot be done by simply checking focus at the film plane with piece of ground glass, or can it? I doubt one could see a tiny amount of misalignment this way.
Without knowing (seeing) where the shims were, it's hard to say. I'll assume the focussing screen is fixed and not shimmed. You need to place the mount flange surface a specific distance from the filmplane as well as perfectly square to the film plane. I'd use a surface plate, gauge blocks or precision parallels to rest the camera on, and a good dial indicator reading to .0001". Focus would be checked by viewing the aerial image at the plane,(both film and GG) not on groundglass. Next time record where the shims were and replace them precisely as they were.
Good luck.