This is a very beginner question, but hoping somebody can help! I'm just in the process of learning about exposure, aperture, shutter speed, etc. as i'd like to use the manual mode more often. I'm at a point where i'm comfortable enough now to venture out and try to snap some photos in manual mode. One question...is it possible to use auto focus in manual mode, or are you forced to use manual focus? I notice that in manual mode I can't hold down the shutter button half way to engage AF. Any info would be helpful! Thanks.