Ok... So at 8:20 this morning you posted on here, asking for help. Then, at 5:10 this evening you thanked everyone for their help, and also informed us that you had pulled the trigger, and got a used camers, and lens.

I am assuming that you did not follow any of the very good suggestions posted here, and went ahead and bought from a business that many here have never heard of, And from what I have read, their sales practices may be quite suspect. You were even directed to a couple of very highly rated companies(B&H, Adorama, and Hunts). Please inform us where you decided to "pull the trigger". I, for one am very curious.

All that being said, if this comes back and bites you on your tail, it is totally on you...You have no ground to stand on, to complain someone here gave you bad information....

I really hope this deal works out for you, but, you were warned.

It’s FoCal. Without seeing your curves, I would guess that one thing you’ll find in common with all your lenses is that the acuity starts to drop somewhere between f11 and f16 due to diffraction. On the other end, some are sharpest wide open while some are sharpest several stops down. If you want to label them, you could put the sharpest aperture and the lens type on the lens cap with a label, BUT, in truth, it probably won’t matter. Why? Because you’ll probably make your aperture decision based on the DOF you want to achieve, rather than where the lens is sharpest, and secondly, the acuity probably doesn’t vary more than 10-20% across a couple of stops unless you get near the point where diffraction sets in.

If I may ask, what measurement did you see that makes you feel that the 200-500 is defective at the long end? Is the suggested calibration out of the adjustment range?