Canon EF 400mm F2.8L IS III USM is an Auto Focus (AF)
Telephoto Prime lens with 35mm FF max sensor coverage and it is designed to be used with Canon EF mount cameras.
Lens Mount
Canon EF 400mm F2.8L IS III USM is compatible with cameras that have Canon EF lens mount.Some of the latest released cameras with Canon EF lens mount are
Canon 1D X III,
Canon 6D MII and
Canon 5D MIV.
Sensor Coverage
Max sensor coverage of Canon EF 400mm F2.8L IS III USM is 35mm FF.
Focal Range
Canon EF 400mm F2.8L IS III USM has a fixed focal lenght of 400mm. When mounted on a 35mm FF format camera, it provides an 35mm (FF) equivalent of 400mm.
Optical Image Stabilization
Canon EF 400mm F2.8L IS III USM features an optical image stabilization system which helps to reduce the blur that occurs due to shaking during hand-held shooting.
Aperture
Canon EF 400mm F2.8L IS III USM has a max aperture of F2.8 and a minimum aperture of F32.