Sigma 10-20mm f/3.5 EX DC HSM

The Sigma 10-20mm f/3.5 EX DC HSM is available with lens mounts for Sigma, Canon, Nikon, Pentax and Sony DSLRs, and provides a 15-30mm focal range. The lens features 13 elements in nine groups with one SLD (Special Low Dispersion) and two ELD (Extraordinary Low Dispersion) glass elements designed to combat chromatic aberration.

Sigma 10-20mm F/3.5 EX DC HSM

Sigma 10-20mm F/3.5 EX DC HSM

Autofocus isn’t as quiet or smooth as some of its competitors (the equivalent Canon and Nikon spring to mind), but it does lock onto subjects quickly, so no complaints there. Then there’s a large f/3.5 aperture through the entire zoom range.

The Sigma is a solid lens, which is what you’d expect when it weighs in at 520g. It features a focus switch on the left of the lens, but it is rather stiff. The zoom ring is located where you’d expect it – behind the focusing ring – so a thumbs up there. Unfortunately the focus ring is quite stiff too, and so close to the front of the lens that your finger and thumb rub against it as you focus. The filter size is 82mm, meaning filters and adapter rings will be more expensive than those for 77mm filter threads.

In terms of image quality the Sigma sits just above average for wide-angle zooms. Sharpness in the central area of the frame is very good, but this drops off towards the edges as chromatic aberration increases. This is noticeable in both test chart shots and real world test photos. This lens shows minimal barrel distortion, with the least amount at its widest setting and no distortion whatsoever at 20mm.


This Sigma wide-angle comes in at a very reasonable price for what it is and for its features. It’s also available for plenty of lens mounts. This lens is considered by some photographers as the benchmark for APS-C wide-angles, though our tests suggest this may not now be the case. But with very little distortion this remains an attractive lens, especially for the price.


  • Street price: £329 (As of June 2016)
  • Maximum aperture: f/3.5
  • Minimum aperture: f/22
  • Construction: 13 elements in 10 groups
  • Number of diaphragm blades: 7
  • Minimum focus: 24cm
  • Filter thread: 82mm
  • Weight: 520g
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This review was first published in the September 2012 issue of Digital Photo - download back issues here.