Thanks but this is one case where really good gear helps a lot. I've played around with a lot of lenses, old manual stuff, adapted, modified, etc.
One mistake many make is too slow shutter speed. The moon moves fairly quickly, and "faster" of course the longer the lens This was taken at ISO 400, 1/250 sec. I would not want much slower.
This 300 mm 2.8 is so old it was built BEFORE consumer digi stuff came out, IE built for an AF film camera. When it was new it was something like 5K. The new replacement is the "II" model, with IS, and it's about 7K. I paid something like 400 bucks for this. The guy was truthful, and told me "I'd probably have to manually focus it" because the AF is off. Turns out my 7D, which has a menu item to correct front/ back focus, had the adjustment range needed.
It's so beat up, I could lie and say "I've been to the Himalayas" er some darn thing, it looks it!!!
One reason I bought the 7D over my 40Ds was the larger, better LCD (magnified live view focus) and the yet larger viewfinder. Unless they get stolen or broke, I won't be buyin' any more cameras!!!!!