This is a question I've been wondering about for a while, so I decided to go ahead and ask it. I've noticed that on several of my lenses (for both my Canon and my K1000... see my profile), the focusing ring allows me to focus slightly past infinity, i.e. when the lens is focused at the farthest possible object, I can still turn the ring a little farther and make it out-of-focus again. I was wondering what function this extra focus serves? Theoretically there should be nothing it can focus on past infinity, so why can I focus to it? Wouldn't it be nice and easier if it could just stop at infinity so I knew exactly when it's focused on a distant object? So, any ideas?