Bob:

I do not have the 500, but I did use this with my 100-400 and the results matched my manual method. A couple of suggestions:
  • They suggest printing the target at 300dpi. On my printer that did not look good so I printed at 600dpi which was way better.
  • Make sure the paper and ink is not reflective, and make sure your lighting is consistant throughout the test (clouds moving in and out is not good).
  • I know you are supposed to be 50 time the focal length for optimal testing, but you would be better off at the distance most shot from. Aslo, when I did my manual testing, I did it at the recomeneded distance and came up with an adjustment of +5. Then using the FoCal at a much closer distance (about 8 meters) I got the same results several times in a row. I guess I would suggest a shorter target distance. That is not normal practice, but it seemed to give me expected results.
  • Did you turn off IS? If you did not, then that would make your live view drift in and out (FoCal suggests it be turned off).

Not sure that will solve you problem, but it is what I did.

Also, I was supprised at the results I got with my macro lens, but after checking it out at the setting suggested by the testing, it seemed to be correct.

Pat