The autofocus of this objective poses problems with Sony Alpha see previous post: - A37 erratic, - And with the A57 no action. In manual adjustment, you get great pictures. It should be noted that this objective worked perfectly with my old Minolta 7D. Sigma offered me a return to service for the update, but I decided to return the lens. Because in the future, during a change of aircraft, I did not have the certainty of proper operation. If Amazon's service perfect for return and refund.
