Canon EF 400mm f/4 DO IS II USM Preview: Optically improved 400mm super telephoto prime from Canon

Weighing approx 2100g the optical arrangement in the Canon EF 400mm f/4 DO IS II USM makes it roughly half the weight of the f/2.8 versionCanon 400mm f/4 DO IS II USM Specification: Slightly heavier but better optical performance?If you make your money from sports or wildlife photography, or just take it very seriously, a top quality super telephoto lens is a must. The new Canon EF 400mm f/4 DO IS II USM is an updated version of its predecessor, featuring a revised optical arrangement, with new lens elements and coatings, to improve its optical performance. If