Light But Powerful: A Review of the Canon EF 400mm f/4 DO IS II USM Lens
The Canon EF 400mm f/4 DO IS II USM lens is a rather unique lens that takes advantage of Canon's diffractive optics technology to help create a lighter and shorter design, perfect for people like wildlife photographers who have to lug around large lenses. This excellent video review takes a look at the lens and the kind of performance you can expect.