Great investment! That lens you have has the same focal lenghth as one of my astronomical telescopes! Cool.... Cute bird....at that focal length you'll need a very stable tripod, as I'm sure you know, and the use of cable release is probably a given. A few stops down wouldn't hurt the moon shot, but it still looks a bit blurred, I'm not sure if that is because of movement or slight imperfections in the mirror/lens. You were right azy, this would have been very handy at the whale watching! :-)>