Canon 400mm f4.0 DO IS 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 lenses.
Canon 400mm f4.0 DO IS USM was replaced with Canon EF 400mm F4 DO IS II USM. Follow the link to read our comparison of these lenses:
Compare Canon EF 400mm f4.0 DO IS USM vs Canon EF 400mm F4 DO IS II USM
Lens Mount
Canon 400mm f4.0 DO IS USM is compatible with cameras that have Canon EF lens mount.
Sensor Coverage
Max sensor coverage of Canon 400mm f4.0 DO IS USM is 35mm FF.
Focal Range
Canon 400mm f4.0 DO IS 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 400mm f4.0 DO IS USM features an optical image stabilization system which helps to reduce the blur that occurs due to shaking during hand-held shooting.
Body Colour
Grey and Black
Aperture
Canon 400mm f4.0 DO IS USM has a max aperture of F4.0 and a minimum aperture of F32.0.