[bobbotron]

I recently bought a new in box Jupiter 8mm fisheye. On my spotmatic F, when it's screwed most of the way in, you can feel it rub against something. On my Honeywell spotmatic it screwed in ok but the mirror would return after a shot! If I unscrewed the lens slightly the mirror would return.

Is this a common problem with some lenses, is there anything I can do about it?

[stevebrot]

Is this a common problem with some lenses, is there anything I can do about it?

Yes, rear element clearance was an issue back in the day and not just for Asahi. Mirrors that were long enough to work well with longer lenses were often not compatible with lenses originally designed to work with other bodies. T-mount lenses were a common source of incompatibility to the extent that camera body reviews would often include a check against popular 3rd party offerings. The best solution was to design an articulated mirror movement to swing the mirror edge back before swinging it up. That being said, most makers used a simple hinge.

Your options are either shave the mirror* or the lens. If the interference is on the metal part of the lens, you may be in luck.


Steve

* Users of current model Canon FF dSLRs have similar issues with the protruding rears of many vintage lenses. Shaving the mirror is the common remedy.

[Xmas]

Nikon F, F2 and some Olympus OMxx bodies have manual mirror lock ups so you use a direct vision finder on flash shoe.
Many LTM lenses won't fit some LTM or M cameras.
So interchangeability is not only a mount compatibility issue.

[bobbotron]

So I had a suspicion that it was the rear filter that was hitting the mirror. Took it off, no more mirror issues. I threaded it back on and realized it wasn't screwed all the way in! There must have been some paint on the threads, or a bad thread. It wasn't cross threaded, but it sure was difficult to screw in all the way. Once I did, the mirror issues were totally gone! Mystery solved!

[stevebrot]

So I had a suspicion that it was the rear filter that was hitting the mirror. Took it off, no more mirror issues. I threaded it back on and realized it wasn't screwed all the way in! There must have been some paint on the threads, or a bad thread. It wasn't cross threaded, but it sure was difficult to screw in all the way. Once I did, the mirror issues were totally gone! Mystery solved!

They need a happy dance icon for this site. Good work


Steve

[bobbotron]

They need a happy dance icon for this site. Good work

Steve

I was super happy to solve the problem! I really didn't want to give up on the lens, hopefully someone else with one of these lenses will see this thread if they have the same issue.