The Canon RF 400mm F2.8L IS USM is a super-telephoto prime for the company's full-frame mirrorless system.

The lens, which uses the same optical formula as the EF version, features 17 elements in 13 groups, with one super UD and two fluorite elements. Super Spectra and Air Sphere coatings reduce ghosting and flare. The image stabilizer reduces shake by up to 5.5 stops.

The lens has a minimum focus distance of 2.5m (8.2 ft) and a magnification of 0.17x. Three focus limit modes are available: full, 2.5-7.5m and 7.5 to infinity. The 400mm F2.8 supports 52mm drop-in filters and Canon's