11-25-2016, 11:19 AM
I believe Canon does not use hard stops at infinity for USM lenses. They claim that focus is reached when you over shoot the focus then back off. Even most MF lenses go beyond infinity. A hard stop at infinity is very nice to have though. My EF 50/1.8 Mark I hard stops at infinity. It is not USM. Neither is the EF 50/1.4 (although it does say ultrasonic on it). I wonder if it has the infinity hard stop?