Sigma 17-70mm f/2.8-4 DC Macro OS (Optical Stabilizer) HSM Lens for Canon EOS Cameras

I've had this lens for about 2 months. I have a Canon Rebel XT with the older 18-55 II non IS lens. It was nearly impossible to get good pictures of my kids unless we were outside in good light. Now, that's not as much of a problem. The wider aperture allows much more light to hit the sensor giving me more keepers. The macro abilities are much better as well. With the 70mm zoom and the close focus distance, I can get great pictures of flowers and such. It's not close enough for shots of insects, but bees and dragonflies will work, if they sit still long enough. Before the 18-55 was a limiting factor in my pictures, now the Rebel is. With the older 8 megapixel sensor, it is easy to get sharp pictures right down to the pixel level. The ability to use faster shutter speeds and the addition of the OS on this lens helps. If you have the newer 18-55 is II lens, I don't know how much of an upgrade this is. But for someone like me that is still living in the dark ages of dslr photography (and will be for a while) this is a worthy upgrade. I'm not getting great vibrant colors with it, but I never did with my 18-55 either. I don't know it it's the camera, lens or just me.Pros:Feels durable/solidOS works well. Took a hand held one second shot while braced. Couldn't blow the picture up, but works for sharing.Zoom and focus rings work smooth.Image quality is great. I've had a lot of positive comments about the pictures I've taken with it.Front element does not turn during focus. Great for polerizers and gradient filters.Much improved auto focus ability over 18-55Wider aperture allows for a brighter viewfinder. Better for composing shots in lower light.Cons:Much heaver then the non IS version of the 18-55. Not sure about the newer ones.Focus ring is right next to the zoom ring, and turns during auto focus. I had to adjust how I hold my camera.No full time focus. I have to switch to manual to adjust focus.AF/Manual focus switch is a little hard to move, could be a good thing, and I may get used to it.Lens cap doesn't snap on tightly, I have to snap it on, then screw it tight.The cons are a bit more nit picky then anything really. For anyone with an older 18-55 looking for an upgrade, this is a great choice. I can't compare this to the 18-55 IS II lens however. There are plenty of reviews comparing to other lenses. For the money, this seems like a good bet.

If there was only one lens I could chose to bring along with me anywhere, it would be this Sigma 17-70mm without a doubt!I rarely have a specific photo shoot in mind when I go anywhere. So usually I would bring two or three lenses with me just to cover all the focal lengths. But that obviously gets bulky and heavy pretty quick. This lens covers wide-angle at 17mm with f/2.8 all the way to medium/telephoto at 70mm with f/4. With that range, I don’t even need to bring anything else with me on a daily basis which is a huge deal!It’s a fast lens that still stops down enough to photograph silky waterfalls with slower shutter speeds. At the larger apertures, the out of focus areas (bokeh) are not super smooth, but still look great and not at all a deal breaker. Like other Sigmas, it’s also not as sharp at larger apertures, but still not a deal breaker.The autofocus is fast and accurate! The motor makes just a little bit of noise, but I hardly ever notice it. I enjoy photographing motocross races which are very fast paced. With the continuous autofocus set, it tracks the racers no problem. The optical stabilization also comes in handy during the races. I’m able to get blurred action shots with the racers perfectly sharp.With all the great features of the Sigma 17-70mm, coupled with the unbeatable price, it’s the perfect lens for the photography enthusiast that wants to bring versatility and range to their run-and-gun setup, but not break the bank.

I have seen many rumors that this lens is soft at 17mm. After two full days of testing I can put that rumor to rest, this lens is so tack sharp throughout the entire zoom range its hard not to cut yourself on it. At 17mm and f/2.8 the out side edges are slightly softer then the center. But to notice this you have to take multiple photos and zoom in over 300% and really "really" try to look for it. I tested this lens on a Canon Rebel T3i (600D) with a 18mp sensor. I can't say how impressed I am with this lens in terms of both optical and build quality. If you are looking to upgrade from your kit lens or just need a new lens in this zoom range without breaking the bank. Get this one. The only lens on the market for Canon in this zoom range that offer better optical quality is the much more expensive Canon 17-70 f/2.8L Lens. But its optical quality is very very marginal over the Sigma.Pros:- Half stop better lighting performance over most kit lens.- Better construction over most kit lens.- Most importantly, better optical performance over most if not all kit lens.- Does not suffer from zoom creep depute no zoom lock.- Comes with Tulip Lens Hood.- Tight yet smooth zoom even for video.Cons:- No full time manual focus override. You must turn off AF to use manual focus- The focus ring is little to close to the zoom ring.- No weather sealingOther Thoughts:I got this lens to replace my Canon EF 28-135 IS USM Lens. This lens is so much better in both optical and build quality that its jaw dropping. The OS works great, very quiet and the lens is very fast focusing. I can't comment on how this lens would be on other Camera brands like Nikon. But rest assured that if your a Canon user you will love this lens.