I thought my 2nd EF 50mm 1.8 II might be front focusing so I've loaned it out to a couple of people and they seem to think the same. Its not enough to make the lens unusable if your aware of it.
So my question is, what causes a lens to front/rear focus. How do you fix this (assuming you can't send it to someone to do it for you). As this lens cost so little its not worth repairing it, I'm tempted to open it up and try fix it myself but I've no idea what to look for inside it.
Assuming the 5 cameras this lens has been on don't all front focus the same amount. Is it a case of something being too loose or to tight in the lens? Has a gear skipped a tooth when it was manufactured. What are the variables that feed into lens focus issues?