This lens has an EF type mount, that fits the Canon EOS line of cameras. It was introduced in January 1993. Featuring the highest magnification (10x) of any interchangeable SLR lens at the time, the lens was and is popular among photojournalists. It has now been superseded by the Canon EF 28–300mm lens. When used on a digitalEOS body with a field of view compensation factor of 1.6x, such as the Canon EOS 7D, it provides a narrow field of view, equivalent to a 56–560mm lens mounted on a 35mm frame body.
The lens contains 21 elements in 15 groups. As an L-series lens, it features two ultra-low dispersion (UD) elements, and utilizes Canon's ring USM for fast and silent focusing. It has a push-pull zoom design with the possibility to lock the lens at the desired focal length. The lens exhibits strong barrel distortion and chromatic aberration at the wide end. On an APS-C body, the lens shows almost no vignetting, even at its maximum aperture, f/5.6, at 350mm.