Quote Originally Posted by gschaps View Post
How often do you adjust a camera/lens combination? The 6D manual says you should do it on site, which leads me to believe often. Thanks.
Not often. The reason for the 'on site' recommendation is that AFMA is distance-dependent. Many times, what works at 25-50x the focal length (recommended calibration distance) doesn't apply with very close subjects.

I calibrate each new lens on each body when I get it (and all lenses to a new body). I test them again every 6-9 months, but they're stable (unless you drop your camera - I did that to my 5DII, 3' to pavement, not a scratch the body worked perfectly, but all my AFMA values shifted ~10 units to the negative relative to the original values).