09-29-2010, 10:17 PM
After playing around with the 16/2.8 my opinion is that a strong field curvature is producing the bad corners. If you do MF you can easily get the corners sharp at 2.8. Have you focused on the woman? And is there not a Canon lens with a similar problem? ;-) I don't say that the 16/2.8 is the best since sliced bread but it is good enough for may tasks.