RPT - ah, but you forget the 500mm is f4 and a 2x TC takes it to f8 so f5.6 would be tricky!Ah! Clean forgot about the 2x. Thanks for the detailed description. Still waiting for the rains to abate. Yesterday I got caught in a downpour and was drenched through and through! The darn monsoon does not want to leave! Well, at least the atmosphere is getting a scrubbing
As many lenses are sharpest when stopped down a couple of stops, I thought f11 would be a good compromise (I understand that diffraction kicks in around here on the 5D3 but only if you look for it in shots taken beyond, say, f16 - cue the naysayers on that topic!). Clearly depth of field isn't an issue but maximising sharpness/detail was, hence the stopping down. The moon was very bright but you're still shooting through an awful lot of atmosphere which will soften the image. At ISO 320 I wouldn't really have any noise to worry about and with it tripod mounted, I manually focused in Liveview and set things to mirror lock-up, 10sec timer to allow most vibration to dampen down and IS mode 3, crossed my fingers and the rest is history.
Hope that clarifies things.
Hope to post moon shots when the clouds roll out.