I have been trying to get some pics of the moon when its at it fullest and can only get a very average shot of a white ball with no definition of any features on the moon, I am using a 50D with a 100/400 lens and tried using auto and various other modes on my tripod but still not happy with the results. What lens do people use to get the pics that show craters ? I have a telescope so maybe I need an adapter to use it as a lens.