I am currently using a D300 and a Nikon 70-300 4-5.6G lens among a ton of other equipment. I don't have a lot of use for a strong zoom like this but when I do use it, it seems the focus is off. I use only one focus point and when I look at the photos later on it seems the focus is a couple of feet closer to the camera than where I chose the focus spot. 2 questions. I realize this is a very cheap lens and wonder if someone can suggest a better one in the same (or close to) zoom range at a decent price? Also, I understand the D300 can adjust the focus for certain lenses. Can someone explain this to me? Thanks!