I hope I am posting this in the right forum. It concerns A Canon body and a non Canon lensl. I currently shoot with a Sigma 17-70mm lens on a Canon XTi body. I have benn less than 100% happy with the Sigma lens since I got it. It seem to produce out of focus photos - at times - mostly at distance (infinity). I recently contacted Sigma Corp. Customer service responded rather quickly, twice. The first response was from a customer service rep who stated that it could cost up to $100.00 to calibrate. I then made the decision that I just would not buy another Sigma lens,, and stick with Canon lens. A day later I get an E-mail from a different Sigma customer service rep that says they will calibrate it for free,, but I have to send them my Canon body and the Sigme lens. I am quite hesitant to do this, and at this point I feel that I will revert back to my - not buying Sigma products any more. I have heard many times of folks getting their lens calibrated, or re-calibrated,, but does the camera body have to be shipped with it in order for the lens to be adjusted? Any insight would be greatly appreciated.