( Yay! I just did the shift reload thing and it worked !! )
>>you probably had Active Dlighting on .. if you have the Raw file the halo should not be there.<<
Yep, that's it. Fortunately I shoot RAW+JPEG so I have backup. Nasty side-effect of Active-D. Think I'll shut it off altogether, or at least set it to minimum.
>>Yes - atmospheric conditions. Without being technical you are seeing the light reflected off the moon onto the atmosphere of the earth.<<
Yes, and apparently Active-D did a mambo on it. Nasty.
Like all the other settings, you need to know what Active D does and when best to use it. I usually have mine set on Maximum and turn it off when I need to or use the RAW/NEF. Active D Lighting is a very nice inclusion. You just need to know when to turn it off :-)