Can we talk about how everyone blames the lens when the mount screws are loose?
Had a customer bring in a Canon FD 50mm f1.8 last Tuesday. Swore up and down the glass was decentered because one side of every frame was soft. He had already sent it to two other shops in Columbus who both quoted him a full element realignment. I put it on the collimator and the optics were dead straight. Turns out three of the four mount screws had backed out about a quarter turn each. Tightened them, checked flange depth, shot a test roll. Sharp corner to corner. He paid $40 instead of $300 and looked like I had just cured his dog. How many lenses get torn apart for problems that live in the mount?