Photoxels have published a guide to Area Focus, which apparently is one of the three focusing modes found on newer digital cameras. I must admit to never using or seeing this feature before, but if your camera has this mode and you’re unsure of how to use it, then the Photoxels tutorial is a good read.

“Area Focus extends Center Focus by allowing the AF frame to be moved anywhere on the screen. So now, if your subject is to the left of center, instead of moving the camera left, pre-focusing and then moving the camera back, all you do is move the AF frame left instead while keeping the camera still!”

Website: Photoxels - Area Focus Tutorial