Excerpt: The out door pics were ok but the indoor low light pics were horrible at best every face had orange tint in them & poor low light in back/sides of the subject almost blacked out.I would never recommend this lens to anyone !
Excerpt: Just tried this lens out for the first time. Hunts for focus forever regardless of amount of light. When it does happen to autofocus it's often not even close to being in focus. Maybe I got a bad sample? All my Nikon lenses have no trouble focusing under the same conditions. Will be exchanging this one... essentially unusable.
Summary: Tried it with a d7000 and it can't lock on an object when autofocusing. Lens was sharp but the autofocusing problem was a dealbreaker for me, tried it on my backup body and same issue. Returning it.
Excerpt: I used the Sigma 17-50 at a wedding because of its 2.8 capability but was disappointed because of its depth of field not resembling what a Canon would look like at a 2.8 mm. At 2.8 the photos looked more like 5.6. I have been shooting weddings for about 3 years and decided to give this lens a shot but it was returned right after the wedding. The photos were noisy at medium to low light but nice in daylight at an f stop of about 5.6 and up. The lens did poor in low light.
Summary: I bought this for my Nikon D7000 and specifically so I could photograph an upcoming indoor sports event my sons would be in. The first one arrived. Build quality seemed good. However, it would not autofocus - it would just hunt forever and never lock on. I exchanged it for another one which arrived the day before the event. It did exactly the same thing. Lighting levels were irrelevant, neither indoors nor bright outdoor sunlight would allow it to lock on.