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Sigma's original 10-20mm f/4-5.6 ticked pretty much all the right boxes, and rapidly became a top seller for users of Canon, Nikon, Olympus, Pentax, Sigma and Sony bodies alike.
There was a lot to love, from Sigma's fast and ultra-quiet HSM (hypersonic motor) autofocus with full-time manual override, to solid build and impressive image quality. To top this, the lens came at a knockdown price that put a few own-brand lenses to shame.
The Sigma 10-20mm f/3.5 EX DC HSM is Sigma's new version of the already popular lens and it goes further still, with a major redesign that ushers in a constant maximum aperture of f/3.5 throughout the zoom range, making it one the fastest lenses on the market.
For the first few months after launch, the advancements came at a high price to buyers, with the street price being about £210 more than the older version.
But it's since dropped dramatically, and the price difference is now only £50.
Quality counts
Internally, the lens is quite different to the older model, featuring an extra element in one of its groups, and four aspherical, one SLD (special low dispersion) and two ELD (extraordinary low dispersion) elements.
Considering the Sigma is one of the cheapest lenses of its type, it's very well built, with a high-quality feel, impeccable finish and some neat touches, including the distance scale being positioned beneath a viewing window.
As usual, Sigma doesn't skimp on accessories either, and the lens is supplied with a plush, padded soft case, along with a quality petal-shaped hood.
