Before you buy, read this. Great lens but too heavy for casual/enthusiast use
Coconut the Critic, Amazon
3 October 2013
Summary: I have a Nikon D80 and wanted to upgrade my lens selection. This lens is beautifully made and is of pro/semi-pro quality. It is a good value for the money compared to the Nikon 24-70. It takes wonderful, sharp photos, especially at F3.5 range. BUT it is heavy. Too heavy to want to carry around at DIsney World all day in the heat of summer or anywhere else for that matter. The weight is not specific only to this brand.
Excerpt: I've been using this lens to capture city scenes (would not recommend for filming landscapes, portraits, nor interview subjects). A plus is that it's relatively lightweight and provides decent depth of field. A con is that you get a bit of vignette around the edges.
Excerpt: I've been using this lens for a fortnight, and it has an annoying problem with the autofocus constantly focusing just in front of what is under the focus point in the camera. I've tried the autofocus across the zoom range and from F2.8 to F22 without much change. The areas that are in focus are perfectly sharp and the HSm is fast and quiet. But the consistently out of focus images really ruin this lens for me.
Pros: Consistent Output, Durable, Easily Interchangeable, Strong Construction
Excerpt: I have struggled with the decision Canon 24-70 L or Sigma 24-70 HSM ex, I have read every single review, on every single site. I decided to go with the Sigma. My wife insists that if I read a good Sigma review , that it was secretly written by the Sigma company and the same if it's a strong Canon review..I don't work for either company.
Excerpt: When I first bough this lens, I noticed that subject was up close the lens focused perfectly, great bokeh, great colors, fast focus. Move the subject away and wham, back focussing issues. <br /><br />So I sent it into Sigma. They sent it back, it back focused worse. So then I sent it again - this time with my 5D, it came back, still back focusing. I sent it in a THIRD time - this time to Sigma HQ in NY with my 5D again.
Summary: I probably just got a bad copy, but boy was it bad. Terrible wide open and not all that sharp stopped down. I was comparing it against some Nikon glass and it just wasn't looking good. I sent it back to Amazon the next day. The quality seemed nice, but I also didn't like the 82mm filter thread. I have a ton of 77mm filters, so this was going to be a pain. I've been told by others that their copy was razor sharp, so maybe I just got unlucky.
Excerpt: I read all the good reviews and ordered one. I put it side by side against a l series canon lens owned by a friend. I tried 24mm and 70 mm at f2.8 f4.0 f5.6 and f8.0. Every picture with the l series was better. I returned this lens. I think this lens is of good quality. I just knew if I kept this lens I would always question every picture I took with it.
Excerpt: This lens exhibits many fine features - very well built, nicely balanced, good color and contrast, quick silent autofocus, pleasant bokeh, excellent macro mode and extremely sharp along the center axis. In many ways, quite comparable to my 28-70mm F2.8L.<br /><br />In this lens, Sigma has delivered an excellent solution for 80% of Canon photographers.<br /><br />Now the bad news. On a body equipped with full frame sensor, that last 20% has proven problematic.
Pros: Consistent Output, Durable, Fast / accurate auto-focus, Very sharp in the center