Hello all! I have a Canon 1100D/T3 and I've been having problems with auto focus on all three of my lenses. Unless the scene has a LOT of contrast, the auto focus just hunts forever focusing back and forth never locking in on anything. This happens with every lens. I don't know exactly how the focusing works, but my viewfinder looks pretty dirty (or I guess it could be the mirror that is dirty). Could this be a possible cause? If not, any ideas?