Sigma 10-20mm f/4-5.6 EX DC HSM £350, $430
One of the first independently-made ultra-wide lenses for the DX format, it’s still going strong
Since its launch in 2005, the Sigma 10-20mm has been a popular option. Despite its budget price, build quality feels robust, and advanced features include ring-type ultrasonic autofocus, with the usual full-time manual override. Handling benefits from the fact that the focus ring doesn’t rotate during autofocus, unlike the similarly priced Tamron 10-24mm lens. The design features three SLD (Special Low Dispersion) elements, aiming to reduce chromatic aberrations, while the minimum focus distance of 24mm is typical for a lens of this zoom range.
It’s slightly more compact and lightweight than Sigma’s 10- 20mm f/3.5 constant-aperture lens, and has a smaller, more typical, 77mm filter thread, rather than 82mm. However, it’s just over an f/stop slower at the long end of the zoom range.
With its fast autofocus and great image quality, this Sigma delivers very good performance. Levels of sharpness and distortions are very similar to some of the pricier lenses in the group, and better in some cases. As with a number of lenses on test, chromatic aberrations can be noticeable, especially at the short end of the zoom range. Overall, however, the Sigma is outstanding value for money.