I have the Canon 7D and needed a wider angle lens for taking snapshots. This fast reasonably priced lens sounded fantastic. When I got it though the first thing I noticed was how very soft the pictures looked compared to my other lens which is Canon's 60mm f/2.8. After further inspection I noticed it severely front focused. After mounting it on a tripod and doing tests with a chart I used my cameras adjustment to compensate for the the focusing issue.

During Christmas I took several hundred photos and found out that around half of them didn't have proper focus. I returned the lens to Amazon and got another copy hoping this would fix my issues but surprisingly it didn't. I found that if I manually focused the lens then it would produce better results, but even then it wasn't as sharp as my 60mm lens. When you focus manually it feels like there is slop in the mechanism and I suspect this is what was causing the focusing problems.

I then try sending the lens to Sigma in NY and they send it back with a firmware update. I anxiously open it and try it out at my daughters birthday party, but once again I am let down with inconsistent focusing. Finally fed up with all the time and trouble I return the lens to Amazon and get 80% of my money back since I spent over a month trying to get it to work and sending it in to Sigma.

Maybe I simply got 2 bad copies but when I went back to my 60mm I was in awe of how sharp and crisp pictures were compared to the Sigma.

I have now ordered the Canon 24mm 2.8 lens and hope it works better for me. I am really shocked at how bad some of these lenses are when they cost so much. You would at least expect a $400+ lens to be as good or better than a $400 P&S camera.

Keith
I have the Canon 7D and needed a wider angle lens for taking snapshots. This fast reasonably priced lens sounded fantastic. When I got it though the first thing I noticed was how very soft the pictures looked compared to my other lens which is Canon's 60mm f/2. 8. After further inspection I noticed it severely front focused. After mounting it on a tripod and doing tests with a chart I used my cameras adjustment to compensate for the the focusing issue. During Christmas I took several hundred photos and found out that around half of them didn't have proper focus. I returned the lens to Amazon and got another copy hoping this would fix my issues but surprisingly it didn't. I found that if I manually focused the lens then it would produce better results, but even then it wasn't as sharp as my 60mm lens. When you focus manually it feels like there is slop in the mechanism and I suspect this is what was causing the focusing problems. I then try sending the lens to Sigma in NY and they send it back with a firmware update. I anxiously open it and try it out at my daughters birthday party, but once again I am let down with inconsistent focusing. Finally fed up with all the time and trouble I return the lens to Amazon and get 80% of my money back since I spent over a month trying to get it to work and sending it in to Sigma. Maybe I simply got 2 bad copies but when I went back to my 60mm I was in awe of how sharp and crisp pictures were compared to the Sigma. I have now ordered the Canon 24mm 2. 8 lens and hope it works better for me. I am really shocked at how bad some of these lenses are when they cost so much. You would at least expect a $400+ lens to be as good or better than a $400 P&S camera. Keith