This zoom, being an L-series type of EF lens, is designed for advanced amateur and professional photographers. The new zoom also replaced the earlier EF 28-80mm f/2.8-4L USM lens that incorporated the electronic-type of manual focusing rather than the new mechanical-type currently used in most of the latest Canon EF lenses. Having the widely-used focal lengths of 28mm, 35mm, 50mm and 70mm in one lens body is a great idea. In fact, Canon did have an AFD version with the same focal lengths having variable apertures of f/3.5-4.5 that was introduced in 1989. The popularity of that lens with photographers meant they would readily accept an L-series version with a constant maximum aperture of f/2.8. << Back to Main . 1 . 2 . 3 . 4 . 5 . 6 .