10-16-2016, 07:01 PM
Is it worse than with fast Canon glass? I didn't count more blurred results with one or another brand, most of the times it was also me being in a hurry or haven't fully understood how to autofocus. One difficult candidate was the 18-35/1.8, when going wide there was just too much stuff in the AF frames. But that was on an APS-C DSLR. I think, on Sigma's sd quattro the lens is always tack sharp if the AF has had enough time :lol: