The Sigma 400mm F/5.6 lens is a super compact Catadioptric type mirror lens designed for taking fantastic ultra-telephoto shots. Unlike conventional mirror lenses however, it features an amazingly bright F/5.6 aperture to give you ideal fast shutter speed. And it weights a surprisingly light 550g (19.4oz.)
A unique rear slot filter drawer system makes filter changing fast and easy. And a special macro capability gives you 1:4.3 magnification at 2 meters.
Angle of view: 6 degrees
Optical construction: 7 elements in 7 groups
Diaphragm operation: Fixed
Filter size: 30.5mm rear 86mm front
Minimum focusing: 2m
Weight: 550 grams