Originally published March 2005.
WHAT YOU SHOULD KNOW:
Sigma's first from-the-ground-up digitally optimized macro lens (i.e., not retrofitted for digital application) throws a full-frame image circle. Result? On a 35mm SLR, it delivers 1:1 magnification, but on a DSLR with an APSsized sensor, it delivers 1:5:1-1:6:1 overlife- size magnification. It's also the shortest fixed-focal-length that will mount Sigma's 1.4X and 2X teleconverters (although AF isn't possible with the 2X).
At almost 5.5 inches long and 2 pounds (with tripod collar), this lens will strike many as big. Compared with similar macro optics, such as Sigma's 2.5-pound, 180mm f/3.5, however, it's svelte. The barrel is finished with Sigma's matte black "Pro" surface, and features distance and magnification scales. A focus limiter has settings for full, 1.7 feet to infinity, and 1.1-1.7 feet; the latter comprising the range from 1:1 to 1:2. The broad, ribbed rubber manual-focusing collar's action is well-damped through a long turning radius -- well-suited to precise focusing. AF is quiet and accurate, if somewhat slow.
IN THE LAB:
SQF data were across the board excellent, with virtually no discernible distortion as determined by DxO Analyzer 2.0 tests (minimal 0.34% pincushioning). Light falloff was gone by f/4. At the close-focusing distance of 15 inches (1:1), center sharpness was very good at f/2.8 and otherwise excellent. Corner sharpness was identical, except for f/22, which was very good. Optimum performance at f/8.
Unusually fast for a macro tele (most macros longer than 105mm are f/3.5 or f/4), this lens will please nature photographers who will reap edge-to-edge sharpness for their close-ups and faster shutter speeds that help freeze wind-blown flora and squirrelly fauna.