Maybe somebody here has observed the same problem: yesterday the focus of my 35/1.4 L lens stuck in the middle of the focal range, around 0.7 meters. It both affects AF and MF. The lens still focuses towards close range, but does not go to infinity focus. I suspect that this lens needs to make a trip to a Canon repair facility, but maybe somebody else can share same/similar experiences and what needed to be done to fix it.
I had an simliar issue with 70-200f4, it needed to be repaired by canon. I would suggest sending in your body also so they can calibrate the lens to body and you will get 2 goods in 1 go.
Thanks for the replies - yes, will send the lens in. Not sure if it was dropped (it might be likely) - I bought the lens used one year ago from an online retailer, and so far it was working fine. It just suddenly happened without my own wrongdoing.
