Mount: Canon, Nikon, Sigma, Sony A Format: Full frame Construction: 19 elements in 14 groups, nine diaphragm blades Closest focus distance: 47cm Filter thread: 86mm Autofocus: ultrasonic (ring) Dimensions: 95 x 204mm, 1,640g Tested on: Canon EOS 7D
It's practically two lenses in one! The Sigma 180mm is not only a fast telephoto prime with an f/2.8 aperture, but also offers 1.0x macro magnification at its shortest 47cm focus distance. There's often a compromise in autofocus speed with this sort of lens, but we'll come to that later.
The Sigma is available in Canon, Nikon, Sigma and Sony mounts, all with optical stabilisation. In our tests, it gave close to a four-stop benefit in general shooting, but was largely ineffective for extreme close-ups – which is only to be expected from any stabilised macro lens.
Build quality is robust but lacks weather seals. It includes three top-grade FLD elements and a tripod mounting foot is included – just as well, given the need for tripod use in macro photography and this lens's hefty 1.64kg weight.
Like most macro lenses, the Sigma has a long travel distance in its manual focus ring to enable precise close-up focussing. It's surprising, then, that the autofocus is so fast, snapping into focus even over large changes in distance. There's a three-position focus limiter switch, for locking the autofocus range to either end or enabling full travel. Sharpness and contrast are excellent, both at the centre and into the corners, even at its widest aperture. The Sigma 180mm f/2.8 is pricey, but it's an excellent dual-purpose lens.
Sharpness: The Sigma 180mm gives little away to dedicated telephoto lenses – it loses out only slightly to the excellent Canon 70-200mm f/4, for example.
Fringing: There's not normally any fringing in evidence, although this lens doesn't score quite as well as some regular 70-200mm telephoto lenses.
It's a prime (non-zoom) lens, so it's no surprise that the Sigma produces almost no distortion at all (just the barest hint of pincushion, which is usually impossible to see in images).
Verdict: Absolutely excellent, the Sigma 180mm f/2.8 macro delivers equally brilliant image quality for extreme close-ups and general telephoto shooting.