Quote Originally Posted by Heywoodphoto View Post
I'm glad you mentioned lens separation. What exactly do you mean? I have a Computar 105 4.5 and the aperture ring pops down and rotates loosely. Is this a normal function of the lens or is this what you're referring to? The lens otherwise seems fine and when the aperture ring is loose the iris seems to function correctly. Thoughts?
If you unscrew the front elements there is a retaining ring that holds the aperture ring in place. Slip it back into the groove it is supposed to ride in and it will be fixed. Careful that you don't lose the ball bearing while doing so. Keep pressure on the aperture ring after you remove the front elements and don't turn the lens upside down or remove the aperture ring. One of mine does this occasionally. I takes only a minute to fix.

Nearly every Computar I have seen exhibits some separation in the rear elements. Not really worth fixing either due to the cost of it. They are great lenses though. I have three.