[xnau]

Sorry for resurrecting a year-old thread, but I just purchased a Vivitar 70-210 4.5 P/K with the long shield as described here. I found it at a Goodwill store for $30. I removed the ring with the shield just to see if I wanted to keep it and although it did mount OK, the shutter release is affected. When I depress the shutter, the mirror flips up and stays there, no exposure happens. If you rotate the f-stop ring, the mirror does flip back down.

Anybody have an idea what might be happening or if it's possible to modify the lens to prevent this?

thanks

[Stone G.]

Weird behaviour. I would suspect the lens itself to have a flaw. You might try this:

1. Mounted on your DSLR, does the aperture stop down as it should, when the mirror flips up?

2. Mounted on an old Pentax SLR (they might have one in the same store if you don't have your own) with the "shield-ring" in place, does that combination behave as it should?

If either isn't the case, I would assume that the lens is faulty and that the camera waits for the aperture coupling lever to engage (or-something-like-that).

I trust that you do have the camera in manual mode.

[xnau]

Thanks, yeah, it's in manual mode. I've got a thing for old primes. After your comment, I wondered if the linkage wasn't engaging or was jammed. I looked more closely at the linkage and although the iris closed easily on the lens, it seemed to be slightly bent. It straightened it out and voila! Works! Thanks for pointing me in the right direction.

Now I get to see whether it was a good bargain or not...