I've seen a bunch of people say how "back button focus" is better than the standard focus method on DSLR's. I believe what it does is take focus away from the shutter button, so the shutter will always fire when pressed. Instead focus is moved to a button on the back by the thumb wheel - often the AF/AE lock button. Anyone do this? Do you think it is better? I made the change and tried it out today but I had some trouble where it just didn't seem to focus. Maybe I didn't set it up right.