Maybe this has been discussed prior. With the latest deal, I picked up my first Canon 50 1.4. In autofocus, it's great. However, one thing that bothers me is the focus ring... Whether I am focusing manually or full time focus in autofocus, I noticed that there was a friction when I turn the focus ring. Along with the friction, I can hear some sound as the focus ring turns. Unlike the 24-105 or 70-200 or the shorty 40 where the focus ring was smooth like fluid and silent, this one has a drag and some sound as though it was rubbing against something. I realize that the 50 1.4 does not have USM ring type like the other ones. For instance, without evening turning on the camera, if I hold the camera on one hand and then start turning the focus ring on the lens, I can hear the sound and feel the drag. Is this normal or is this a bad copy?