The Sigma 18-35mm F1.8 DC HSM was announced to widespread excitement, if only for the company's sheer ambition in making such a fast zoom. But this inevitably came with a degree of scepticism - it's hard enough to make an F2.8 zoom that's really sharp wide open, so could an F1.8 zoom possibly work?

Super fast constant F1.8 maximum aperture; Excellent optics; even wide open; Fast; silent autofocus; Solid build quality without being over-heavy; Compatible with Sigma's USB dock and Optimization Pro software

Restricted zoom range; Needs detailed AF microadjustment for best results; Inconsistent autofocus in difficult conditions even after microadjustment; Physically rather large for a standard zoom

The Sigma 18-35mm F1.8 DC HSM is an extraordinary lens, offering prime-level image quality in the fastest zoom ever made for SLRs. Its 28-50mm equivalent range is a little limiting though, and inconsistent autofocus means that it can be difficult to make the most of the excellent optics when shooting at large apertures.

Enthusiast APS-C users looking for the very best image quality available from a normal zoom, and willing to spend a bit of time setting up autofocus micro-adjustments or using live view focusing for the sharpest results.;

Photographers who like to travel light, or need a wide-ranging zoom;

The word "groundbreaking" seems inadequate for describing the awesomeness of the Sigma 18-35mm f/1.8 DC HSM Art Lens. The primary reason for that awesomeness is the not-seen-in-any-other-zoom-lens f/1.8 aperture.

Fact of life: fast lenses are expensive, and fast zoom lenses are expensive and heavy. While we can't do anything about its bulk, as long as Sigma's $799 price for its 18-35mm f1.8 doesn't rise to the $1,160 currently in strikethrough type on Sigma's Web site, this lens will remain a great bargain...

The Sigma 18-35mm F1.8 DC HSM lens currently occupies a unique spot as a wide-aperture zoom lens built specifically for APS-C mounts.

Lacks optical stabilization

On paper the Sigma 18-35mm F1.8 DC HSM effectively replaces fast 28mm, 35mm and 50mm equivalent optics in your camera bag, saving space and money whilst offering the convenience of a zoom lens.

Prior to the introduction of the Sigma 18-35mm F1.8 DC HSM ($799 direct) lens shutterbugs with APS-C D-SLR cameras had to make a choice when it came to lens functionality. You can go with a zoom lens and cover a range of focal lengths, but even top-end models only opened up to f/2.8.

Sharp; Wide aperture; Reasonable price tag; Available for several camera systems

Big; No optical stabilization; Some wide-angle barrel distortion.

The Sigma 18-35mm F1.8 DC HSM delivers on its promise; it boasts the speed and sharpness of a prime lens, along with the convenience of a zoom. (4.5 out of 5) Editor's Choice Pros Sharp Wide aperture Reasonable price tag Available for several camera systems Cons Big No optical stabilization Some...

Sharp; Wide aperture; Reasonable price tag; Available for several camera systems

Big; No optical stabilization; Some wide-angle barrel distortion; Modest zoom ratio

Prior to the introduction of the Sigma 18-35mm F1.8 DC HSM ($799 direct) lens shutterbugs with APS-C D-SLR cameras had to make a choice when it came to lens functionality. You can go with a zoom lens and cover a range of focal lengths, but even top-end models only opened up to f/2.8. Or you can opt for a prime lens with a wide aperture, but it doesn't support zooming. Sigma aims to change that with this lens. It's impressively sharp, but it is a bit large compared with slower zooms or fast prime lenses, and its zoom range is modest at 1.9x. It stills earns high marks and our Editors' Choice award; the lens is an accomplishment, and the fact that it doesn't come with a sky-high price tag means that more photographers will actually be able to shoot with it. The lens is currently available to order in Sigma, Nikon, and Canon mounts, but Sigma also plans on offering it for Pentax and Sony/Minolta cameras. It isn't compatible with full-frame bodies; the image circle only covers an APS...

The Sigma 18-35mm F1.8 DC HSM delivers on its promise; it boasts the speed and sharpness of a prime lens, along with the convenience of a zoom.

Sharp; Wide aperture; Reasonable price tag; Available for several camera systems

Big; No optical stabilization; Some wide-angle barrel distortion; Modest zoom ratio

Gary Wolstenholme reviews the Sigma 18-35mm f/1.8 DC HSM A standard zoom lens.

Excellent sharpness; Constant f/1.8 aperture; Low falloff for an f/1.8 lens; Good build quality; Reasonably priced

No real issues to report

The Sigma 18-35mm ƒ/1.8 DC HSM "Art" lens packs a big punch in features and image quality without a big punch to the wallet. Shockingly sharp images at all apertures, even at ƒ/1.8, with excellent flatness of field and good control over chromatic aberration, distortion and vignetting make this lens...