Kukkudrill From Malta, joined Dec 2004, 1122 posts, RR: 5 Reply 9, posted (7 years 5 months 4 weeks 9 hours ago) and read 2373 times:
Thanks for the info guys. And lovely shot Kaz. Seems the Sigma is sharper, but a bit more prone to vignetting at short focal lengths (a problem with both lenses). I've also come across a review by someone who says he tested three copies of the Sigma and they all front-focussed at or near full zoom. He suggested that this was because of an incompatibility with the Canon autofocus mechanism. Kaz have you had any such problems?
Make the most of the available light ... a lesson of photography that applies to life