Sure seems like you need to shoot a flat parallel surface to check the corners. You can't test very well for corner sharpness when the corner is not in the same plane of focus. Naturally the f11 shot is going to look better because it has greater DOF.
-- Best regards, Bruce Wednesday, September 21, 2005, 5:50:42 PM, you wrote: M> on the screen, the brick walls on both shots seem about equally sharp M> to me, except the bricks on the foreground @5.6. can it be a dof effect? M> best, M> mishka M> On 9/21/05, Jim King <[EMAIL PROTECTED]> wrote: >> Cotty- >> >> Thanks for the links; your lens looks good at f16, but so does >> mine. My issue is the poor performance I see when it is used at >> apertures wider than f11. Do you by chance have any shots at larger >> apertures? >> >> Here are two shots (full size) of the proverbial brick wall, one at >> f5.6 (one stop down to give the lens a little slack) and one at f11. >> The one at f5.6 is terrible in the corners, while the one at f11 is a >> lot better. Do you think the one at f5.6 is representative of how >> this lens should perform? >> >> Thanks in advance; any comments from others welcome as well. >> >> (at f5.6) http://www.pbase.com/jamesk8752/image/49615906 >> (at f11) http://www.pbase.com/jamesk8752/image/49615910 >> >> Regards, Jim >> >>

