Quote Originally Posted by Fluvius Camillus View Post
What reason would somebody have to turn it on?
Assuming you don't know much about anti-aliasing as there's no reason for you to play dumb here. Have you ever zoomed in on graphics and seen choppy blocks on the edges that arise from the pixels? Anti-aliasing is a way of reducing those artifacts. I won't get into details. You may have some problems with gamma-compressed formats and I think JPEG is one of them. I personally take shots using the PNG format (game shots, not real photographs haha, those I take RAW).