Canon EF 100mm F/2 USM vs Canon EF 85mm F/1.4L IS USM — Which Is Better?

The Canon EF 85mm F/1.4L IS USM is the more fully featured portrait prime here, launched in 2017 with L-series branding, while the Canon EF 100mm F/2 USM dates from 1991 as a simpler telephoto prime. Both are Canon EF lenses for the EOS system, and both cover full frame, so either mounts on the same EOS bodies and fills the frame edge to edge.

The 100mm F/2 is the lighter and more compact carry, at 460 g and 74 mm long against 950 g and 105.4 mm for the 85mm F/1.4L IS. That 490 g gap leaves the 100mm at roughly half the weight for all-day carrying. Both take front filters, but the 100mm needs 58mm and the 85mm takes 77mm, so existing filters fit only one of them directly.

The 85mm F/1.4L IS is the better choice for maximum light gathering and subject separation, because its f/1.4 aperture is wider than the 100mm's f/2. That extra light helps you keep shutter speed or ISO down for indoor portraits at dusk, and it gives shallower depth of field for isolating a face.

The 100mm F/2 answers with reach and close-up scale. Its 100mm focal length gives 15 mm more telephoto framing for tighter headshots or distant subjects, and it reaches 0.14x magnification against 0.12x. The 85mm focuses slightly closer, at 85 cm against 90 cm. Both are autofocus primes with full manual focus control.

The 85mm F/1.4L IS is the only one of the two built for handheld shooting in difficult conditions. It offers 4-stop image stabilisation, which supports slower handheld shutter speeds than an unstabilised lens, plus weather sealing and a fluorine coating that repels water and oil so the glass wipes clean easily. The 100mm F/2 offers none of these.

Neither lens is teleconverter compatible, so neither focal length extends with a Canon extender.

The 85mm F/1.4L IS uses the more elaborate optical design, with 14 elements in 10 groups including one aspherical element to correct aberrations across its wide f/1.4 aperture. The 100mm F/2 uses a simpler formula of 8 elements in 6 groups, with no aspherical or special-dispersion elements.

The 100mm F/2 offers internal focusing, so its barrel does not extend while it focuses. The 85mm F/1.4L IS does not use internal focusing, so its barrel extends as it focuses.