I had this lens for not very long when the AF stopped working. I cannot focus manually with it either. I started reading some new reviews and found that other people have had the same problem. One or two people have had to have theirs fixed twice and it costs $175 to have Canon fix it. The lens cost almost $400 to start so why invest more money in something that needs work? Shame on Canon for what seemed a very good lens that turned out to be junk. It needs to go back to the drawing board.