Summary: For the price this is a good lens. I've had some pretty sharp results so far. Like most lenses it performs best at around f11. Auto focus is a little slow and can be confused at times. Ok it's not a top of the line lense, but for those of us on a budget, it's a really good lens for the $ Bonus is the lens hood thrown in.
Pros: Durable, Easily Interchangeable, Lightweight, Sharp Focus, Strong Construction
Summary: great, affordable, zoom lens. quality of product could be better and AF could be faster but quality of photos come out greaat! i love it, its one of the bests investments I've made in my life. thanks b&hphoto.. and after your purchase, you'll be thanking them too!
Pros: Easily Interchangeable, Great price, Lightweight
Summary: Bought previous version for my starter lens, and was quite happy. Killed the autofocus after a bit more than a year. Used for sports, taking hundreds of photos a night, so purchased again as I was happy overall. Once again, around the year mark, it died again. I called Sigma, and they said based on my description that the aperture fins are sticking and guessed it would cost about $80 to fix. Would recommend with a warning that it may not last under high use.
Summary: Focused across the room on calendar of scenic view, everyone asked where I was at when I took the picture,all were quite amazed when I showed them the tack at the top of the frame. So crisp and clear.
Pros: Consistent Output, Easy To Clean, Sharp Focus
Summary: Not too shabby for an inexpensive pair of lens. Although the other reviews are right, it does take a little while for it to auto-focus. But takes great pictures! I'd recommend it for anyone who a little short on cash!!