I'm not exactly new to photography, but I am new to the expensive cameras and having interchangeable lenses. I am sure this question is simple and will probably make some of you giggle at me, but hey, I'd rather ask and be sure. Today, I got my Olympus EVOLT E-410, which came with 2 lenses. Each lens has 2 dials. I know the one is for adjusting the zoom, but what is the other one for? Is it a fine adjust for the focus?