Hi, about a week ago I received an old pre-set Cunor 400mm f6.3 lens. I took a few test shots with it while at work, planning to do more serious testing this weekend, as I was very happy with the initial results. Yesterday a friend came by and I showed him my "new" pre-set lens. He didn't know how it worked and while I explained to him, he started fiddling with it. About an hour after he left, I decided to take another few shots, and all of a sudden the aperture, which previously worked fine, started acting up. I decided to open it up, and found that 7 of the 15 blades aperture guide pins were broken off completely. I guess my friend forced the aperture past the pre-set range, doing the damage.
Can anyone tell me how to fix the blades, I thought of gluing the pins back to the blades, but don't think it'll work, or perhaps another alternative is removing the broken blades and spacing the good blades into every second guide. If that won't work I'll remove all the blades and be stuck shooting wide open all the time.
Another lesson learned the hard way, never let anyone fiddle with your lenses
EDIT: If I remove the blades completely, would the aperture diameter be a little bigger / How would I calculate the new aperture?
Last edited by altopiet; 09-14-2012 at 04:44 AM.