Sigma 17-70mm F2.8-4.5 DC Asp. IF Makro

The Sigma AF 17-70mm f/2.8-4.5 DC is a very good standard zoom and a viable alternative to the Nikon offerings in this range. Generally it is capable to produce very sharp results although the corner performance leaves a bit to be desired at 17mm at large aperture settings. The vignetting level could also be a bit better here but most competitors don't offer a f/2.8 settings anyway and from f/4 it follows the mainstream. The level of distortions is about typical for a standard zoom whereas chromatic aberrations (color shadows) are comparatively low. The build quality is very fine for a lens in this price league.

Sigma has positioned the AF 17-70mm f/2.8-4.5 DC macro in one of the sweet spots of the market. It is priced beyond the (usually pretty crappy) kit zooms yet it still remains within the reach of budget shoppers. Even better than that it delivers a performance which matches and sometimes even exceeds more expensive lenses. This includes the in-house competition (AF 18-50mm f/2.8 EX) as well as genuine brand lenses (such as the Canon EF-S 17-85mm f/4-5.6 USM IS). All in all the lens has only one really weak spot - 17mm at wide-open aperture where the extreme border performance is soft and vignetting is quite pronounced (but still not worse than the direct competition). At medium aperture settings the delivered quality is very impressive. Combine that with the quite decent build quality and fast AF and it doesn't need a genius to foresee that this lens will be a quite hot seller.