EF 400mm f2.8L USM

introduced 1991

Focal length and maximum aperture: 400mm f2.8
Lens construction: 11 elements in 9 groups ( including protective glass)
Diagonal angle-of-view: 6°10'
Focus adjustment: inner focusing system with USM
Closest focusing distance: 4 m/13.1 ft
Filter size: 48mm rear drop-in gelatin filter holder
Length x max. diameter, weight: 348 x 167mm, 6,100g