Sigma has produced some really fine lenses over the past few years, including the 50mm F1.4 EX DG HSM (which we liked a lot when we reviewed it in 2008) and the 85mm F1.4 EX DG HSM. But the 35mm F1.4 DG HSM may possibly be its best yet. In fact it's one of those rare lenses for which finding any fault seems almost churlish, so good is its overall performance.
Let's start with the optics. It's remarkably sharp, even wide open, outperforming not only its Canon, Nikon and Sony equivalents, but also the far more expensive Carl Zeiss Distagon T* 1,4/35 in lab tests. Chromatic aberration is also impressively well controlled (both lateral and longitudinal), distortion is low and vignetting more-or-less typical for its class. The rendition of out-of-focus regions is generally quite attractive, although complex backgrounds can end up looking rather 'fussy'. The overall result, though, is a lens that delivers fine-looking images with the minimum of fuss, shot after shot.
There's nothing to complain about with regards to handling either. Focusing is fast, silent and positive, and we've found our Canon-mount test sample to be very accurate too (although this being an F1.4 prime, you've got to take great care over where you place your focus point). The manual focus ring is smooth and precise, and allows the focus position to be adjusted after autofocus. Several small-but-useful touches, such as a ridged grip on the underside of the barrel, and even a redesigned, unusually-positive centre-pinch front cap, all add to the usability. Sigma has clearly put a lot of thought into every aspect of the lens's design.
Equally, it's difficult to find fault with the build quality, which feels reassuringly solid. But one point to note is that Sigma doesn't describe the lens as weather-sealed, unlike its more expensive Nikon counterpart. So if this is particularly important to you, then the Sigma may not be the best choice. The aren't many other obvious reasons not to buy it (although Canon users who value image stabilisation over outright speed, perhaps for video work, should also consider the EF 35mm f/2 IS USM).
