Review of Canon EF 70-200mm f/2.8L USM zoom lens. Canon EOS owners should know of this EF 70-200mm f/2.8L USM zoom lens since it is almost compulsory for every serious EOS camera owner's arsenal of equipment to have one. click for bigger image click for bigger image As one of the finest telephoto zoom lenses in the EF line, its quality is comparable to a single focal length lens. It has four UD (Ultra-low Dispersion) glass elements to correct chromatic aberrations -- those rainbow-coloured hues at the edges of the image. The newly-designed multiple zoom groups for inner focusing bring high image quality throughout the entire zooming range. It is also the first EF zoom lens that is fully compatible with Extender EF 1.4x and 2x. << Back to Main . 1 . 2 . 3 . 4 . 5 . 6 . 7 . 8 .