Canon EF 100mm F/2 USM vs Sigma 85mm F/1.4 DG HSM | A — Which Is Better?

The Canon EF 100mm F/2 USM and the Sigma 85mm F/1.4 DG HSM | Art are both full-frame primes at portrait-friendly focal lengths, 100mm and 85mm respectively. This Sigma record is the Nikon F version, though the Art series is offered for Canon EF, Sony E, Leica L and Sigma SA as well. Canon's lens dates from 1991, while Sigma's Art version is from 2016.

The Canon is the lighter and far more compact carry at 460 g, against 1130 g for the Sigma. It measures 74 mm long and 75 mm across, while the Sigma runs 126.2 mm long and 94.7 mm across, so it takes up more room in a bag. Both take front filters, but the threads differ, 58 mm on the Canon against 86 mm on the Sigma, so direct-fit filters do not interchange.

For light gathering the Sigma's f/1.4 aperture is the stronger tool, admitting more light than the Canon's f/2 for candlelit receptions and stage portraits. The Canon answers with 15 mm more focal length for tighter head-and-shoulders framing from the same position, plus a 0.14x maximum magnification against 0.12x. Both are primes with autofocus, a manual focusing ring and an automatic diaphragm.

The Sigma offers two protections the Canon lacks: weather sealing for shooting in rain or dust, and a fluorine coating that helps the front element shed water and wipe clean of smudges. Neither lens has image stabilization, so sharp handheld results depend on shutter speed or a stabilized body. Neither supports teleconverters.

The Sigma is the more elaborate optical design, with 14 elements in 12 groups including one aspherical and one low-dispersion element, against the Canon's classic 8 elements in 6 groups. The Canon uses internal focusing, so its barrel does not extend while focusing; the Sigma does not have internal focus.