An ultra-wide angle lens at a cheap price, but will it deliver?
The Sigma 10-20mm f/4-5.6 is the cheapest lens in the group. The respectable 10-20mm zoom range is equivalent to 15-30mm on 1.5x crop factor cameras like Nikon and Pentax, and 16-32mm on a Canon body.
It’s available in all the same mounts as Sigma’s new, constant-aperture version of the lens, as well as in Olympus Four Thirds mount (although the effective zoom range of 20-40mm is less impressive at the ultra-wide end on Olympus cameras).
The Hypersonic Motor (HSM) autofocus system isn’t blindingly fast but proved highly accurate and whisper-quiet in our tests. The lens is also very smartly turned out, belying its modest price and featuring the texture black finish favoured by Sigma’s EX series lenses. As with other Sigma lenses, it comes complete with dedicated hood and a high-quality carrying pouch that’s worth having.
The two ELD elements of the newer Sigma 10-20mm lens on test are missing from the older version. The line-up is instead built around three SLD elements and three aspherican elements. On paper, this looks inferior but, in our tests, the lens performed as well as Sigma’s more expensive counterpart and, although sharpness was a lacking when shooting wide open, the optics sharpened up nicely at f/8.