Summary: Checked with my Nikon D5000. Got clear and VERY sharp pictures. Compared with 18-105VR and 18-200VR. Sigma provide much better pictures. Focusing quick even in low light. Quite motor. Built like tank. Good value for money. Update: 08/01/2011 Spent lot of time with lens. Found that color reproduction annoying due to warmer colors. Lower focusing distances means working with PS to fix noticeable distortion. Probably 17-30 is useless range for this lens.
Summary: I bought this lens as a replacement for the kit lens that came with my Pentax K10d. I was unsure about buying a Sigma lens, but Pentax doesn't offer a 17-70mm zoom lens with 72mm objective. Well, it was a good decision. I was very pleased at how sharp this lens is, and its performance in low light. The in-lens stabilization is better than that in the K10 camera body, enabling me to hand-hold at as low as 1/10 sec shutter speed.
Summary: Unless you're flush with cash, a Pentax DA* lens is a bit beyond your financial reach. In a search for a faster alternative to hopefully replace a lens with affordable "glass", enter the Sigma 17-70mm f/2.8-4 short zoom. I bought mine from another vendor and took advantage of a fellow-Pentax owner's coupon codes which brought the price down to $389.00 - including shipping to Alaska. Aside from the good deal, I still had my doubts.
Summary: Great item at a great price. Much better price than a Nikon lens would cost. For anyone who is not a highly paid professional, why would you spend the $$ for a Nikon lens? This item is great and performs without issue. Sigma is a great brand.
Summary: I use this on my SD14 for infrared photography. I use a Canon 50d for standard photography. The lens has a great range and is sharp and relatively fast. I really think this lens is the quality of the EX series. And it if it were 2.8 at 70mm it would probably be designated as one. Excellent build, Very sharp, Fast autofocus for not being HSM. Very much like the 18-50mm 2.8 ex lens.
Summary: The Sigma 17-70mm lens is certainly a sharp lens. It is significantly sharper than the 18-200mm OS lens. This is an average priced, well worth lens to start with. Those using Sigma macro flash may want to get a longer focal lens as the flash cannot function effectively too close to object.
Summary: I'm not a professional photographer, just an enthusiast with ambitions and using a D50. I got this lens to replace the 18-55mm kit lens that came with the camera. While that lens' image quality was admittedly pretty good, I wanted something beefier, and something that could go up to 70mm to close the gap with my 70-210 telephoto. This lens has the best set of features in this particular zoom range out of all the shopping around I did.
Great lens wtih a great price with only minor flaws
C. Haase "Garden Rose Photography", Amazon
17 July 2008
Summary: I love this lens. I really wanted something faster than 3.8 for my portrait work. This lens gives me zoom with the speed I need. My only complaint is that somtimes it seeks for the focus and I have missed a few shots because of this. If you can take your time with what you are shooting this is not a big deal for you. Great Lens!