Summary: I love this lens, I bought it for my pentax K200D, works great with my camera. It's what one would refer to as a snubnose lens. I have purchased sigma lens before and they are good lenses, you will not be disappointed with this lens.
Summary: WARNING if you have a low end entry level DSLR then you will probably want to buy this. This camera lens does not have a motor in it and if your camera does not have a motor in it, it will not autofocus. Wish I would have known before my purchase, or I would have saved up for the nikor 55-200mm.
Summary: The listing indicates that this is an auto-focus (AF) lens. The box and the documentation that came all indicated that it was an AF lens. The actual lens itself was not an AF lens. I don't know if this was just a mistake on someones part (accidentally put the wrong lens in the box) or what.
Summary: I have used this lens in my arsenal for over a year. I have shot thousands of shots with it from fashion to still life to personal landscape details. I love it. I have no complaints or serious critiques.
Summary: I couldn't be more pleased with this lens. The pictures taken with it and my Pentax K-10 camera are crisp, clean and always in focus. It's a great intermediate range lens, and at the price here at Amazon, a real value. I paid 60 dollars less than my local camera store or the Sigma web site.
Summary: I bought this to save some money on a zoom lens but found that the sharpness just wasn't there. I did all sorts of test shots using both the AF and the MF but both really didn't wow me. There is also no image stabilization and I had lots of camera movement in my photos.