8 out of 10 points and recommendedImage quality, low weight, compact size, priceDistortions
It seems that Sigma engineers have done a wise compromise with this lens. They have worked on image quality at the expense of a high degree of distortion. I think it’s a wise solution since distortion is easily corrected via software (I use the excellent PTLens program). The images are crisp and detailed through all the zoom range (simply stop down to f5.6 or f8).reviewed July 22nd, 2006 (purchased for $515)
I use this lens on my Pentax *istDS and I’ve not experienced any major problem with auto focus.
All in all a good lens and a terrific value for the money spent.