I don't know what it is...but for some reason I have been having a lot of trouble lately getting subjects in SHARP focus. I definitely don't trust my own eyes, so I really do rely on auto-focus, or at least the focus indicator according to what the camera says. For awhile now, I've been trying to leave my camera on center-point focus....then I will focus my subject in the center of the frame, then I usually move the frame off to one side (rule of thirds, you know), then take the shot. I guess I'm really just not sure of what types of situations require center-point, select-point, or auto focus. Is it better to use one over the other in certain situations? Last night I took a shot of my wife beside a friend...I'm pretty sure they were almost on the same plane (and distance away from the lens)...so I focused on only one of their faces, then moved the frame to where I wanted it, and took the shot. One of their faces is more in focus than the other. How does this happen? Granted, the photo was being taken in somewhat low-light, ISO was at 3200, and my shutter speed was 1/40. I suppose camera shake could have affected this, but still...one face is definitely sharper than the other. They were both holding still.
Any thoughts / advice are greatly appreciated.
Thanks