http://www.gdanmitchell.com/2008/01/21/corner-sharpness-of-the-canon-17-40mm-f4-l-lens-on-full-frame A daily photograph, news, observations, and ideas about photography Wed, 17 Mar 2010 04:04:06 +0000 http://wordpress.org/?v=2.9.2 hourly 1