Excerpt: On my 6D I was not able to get it to infinity focus. It seemed to randomly front or back focus even on sunlit days. I was using spot center focus also. Micro-adjustment needed +8 for close up focus(where it seemed to focus the most), but that made distance focusing was a lot softer.
Excerpt: Very sharp lens when set at f2.2 or above. Under that and it softens a bit. I thought about switching but it seems that the cannon lens is a little bit worse when it is set to f1.8 or below so I kept the Sigma. Other than that, the lens is made very well and is great for standard portraits.
Pros: Easily Interchangeable, Fast / accurate auto-focus, Strong Construction
Excerpt: I have to admit, in the more than 30-years I've been a professional commercial/advertising photographer, I have, generally, always been brand loyal. In my case, that's Canon. For years, I used the Canon 50/1.4 (going through two of them) and replaced my second one with the Canon 50/1.2.
Excerpt: Well built and sturdy. On my Nikon D300 the focus is fast and accurate with good contrast. I have read horror stories about back/forward focus issues but so far my lens is functioning as it should and I am getting sharp colorful images. I am happy and have no regrets about buying this Sigma lens.
Pros: Consistent Output, Durable, Fast / accurate auto-focus, Nice Bokeh, Strong Construction
Excerpt: I have not had any of the back focusd issues I have read about. Lens is fast and accurate, every time. Lens has a nice solid feel to it and it does have some weight. Front lens is a massive 77mm. Even at F1.4 I get nice clear shots. Stepped up to F5.6 and the result are breath taking.
Pros: Consistent Output, Fast / accurate auto-focus, Strong Construction