I've got a sturdy tripod, and an Arca Z1 ballhead.

Lenses: 70-200 f/2.8 L II or 100-400 L (version 1). I'm going to use f/8, infinity focus.

When I look at the image quality on the website, it looks to my eyes like the 100-400 wins, compared to the f/2.8 with an extender on it.

What about the 100-400 with an extender? It'll give me more reach.

Also, since the moon is still a rather bright object, would +/- EV (let's say, 5 total), be an option, for further processing as an HDR?

Thanks.