Originally Posted by DanielT74 
And finding that 1.7x teleconverter doesn't really give any more detail. Maybe a touch more but also more noise..
This may be completely unrelated to what you're getting at, and forgive me if it's blatantly obvious - but for the best and most dramatic moon shots with lots of craters you need to shoot when the moon isn't full. Crescent moons or half-moons (ie, 1st or last quarter) give the best results.