Had me - was very happy on the 15-85 mm lens - due to various good test releases. But then ... 1. copy was just bad, not a single photograph was really sharp (AF was on!), I doubted already in the camera (Canon 70D), but with different lenses, everything was fine. So exchanged and tested 2. copy. What a difference, center 4.5 star triggers, very well, towards the left edge a bearable sharpness waste (3 star), but then - what a nasty surprise - the right third of the picture is so blurred and out of focus, that the overall picture is actually no longer is usable. Also stopping down to f 8 did not improve the total blur right. Canon confirmed to me by sending various test patterns that the lens must be readjusted .... For more than 600 end customers should not have to be the lens tester for Canon because these your quality control is not carried out in the required manner. Therefore, a total of only 2 stars.
