Originally posted by Kingman What is the solution to slow diaphragm blades opening back to full aperture and a stiff aperture ring? I have tried to "work" the aperture ring and pressing the auto pin many times and that does not seem to loosen things up. The auto aperture pin seems stiffer to press than other fully operational lenses.
Usually sticky blades are the result of gunky old oil on the blades themselves and are not to do with a stiff aperture ring or pin. (Usually with this problem the ring or pin moves fine but the blades are slow to react.) So it sounds like in your lens something is bent, or it was taken apart and not put back together quite properly.