Summary: The flexibility of this lens it´s great. The autofocus it´s a little bit slow, specially if you are taking moving objects, but overall, it´s a great bargain! Pics are not incredible sharp but highly acceptable. In general, Sigma lenses are very good!
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: This is a really well built lens. I found it took great, clear pictures outside. On the down side, it is not for indoor use. To slow, but with this Ap most would be. Again, a great lens for a great price, your next step above this would be to get a IS / OS model with image stabilization, if you can...
Summary: I needed a replacement lens for my 28 - 70mm Sigma Even though this lens only offered f4.0 its still a very nice lens. my other lens was too soft and the pictures were blurry unless i used f8 and above. I am glad i got this lens.