Compact- lightweight- large aperture telephoto zoom lens designed exclusively for digital SLR cameras and incorporating the very latest optical technology.Compact and designed for digital SLR cameras with an APS-C size image sensor- this large aperture F2.8 lens has a compact and lightweight construction of 76.3mm (3.0) in diameter- 135.1mm (5.3) in length and weighing just 770g (27.2oz).F2.8 large aperture over the entire zoom rangeThis lens offers a large aperture of F2.8 over its entire range of focal lengths and its large depth of field offers greater freedom of creative expression. This lens is perfectly suited for low light conditions indoors or at dusk. Excellent optical performanceThe incorporation of the very latest optical technology gives optimum lens performance providing excellent correction for several aberrations. High image quality is assured throughout the entire zoom range. Four SLD (Special Low Dispersion) glass elements are used for utmost correction of chromatic aberrations. Reduced Ghosting and Flare The super multi-layer lens coating reduce flare and ghosting- a common problem with digital cameras and also creates an optimum colour balance. Minimum focusing distance of 100cm (39.4) and maximum magnification of 1:5.3 This lens has a minimum focusing distance of 100cm (39.4). Maximum magnification of 1:5.3 enables close-up photography making it very convenient for taking close-up pictures. HSM (Hyper Sonic Motor) The HSM models provide ultra quiet- high-speed autofocusing as well as full-time manual focus override .Inner focusing and inner zooming systemsThe lens design incorporates an inner focusing and inner zooming systems. The overall length of the lens does not change during focusing or zooming- ensuring convenient handling. In addition- since the front of the lens does not rotate- a circular polarizing filter can be easily attached and use. APO Tele-Converter EX (optional)When this lens is used with the 1.4x EX DG APO or 2x EX DG APO Tele Converters (optional)- the lens becomes a 70-210mm F4 AF telephoto zoom lens or a 100-300mm F5.6 AF telephoto zoom lens respectively.