Sigma Zoom Wide Angle-Telephoto 28-70mm f/2.8 EX DG Autofocus Lens for Canon EOS

This compact, large and constant F2.8 aperture zoom lens and is ideal for digital SLR cameras. Two SLD elements and four aspherical lenses provide the ultimate correction against distortion as well as all types of aberration, especially spherical aberration. Its advanced optical design ensures high performance throughout the entire zoom range. Compact, lightweight Zoom Lens The use of aspherical lenses in the construction of this lens not only corrects aberrations but also produces a very small and lightweight lens design. Its compact, yet robust, construction has an overall length of 87.2mm (3.4in.), maximum diameter of 74mm (2.9in.), filter size of diameter 67mm and weight of 510g (18.0 ounces). F2.8 large aperture over the entire zoom range This 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. It covers wide angle to medium telephoto and is ideally suited to a wide range of subjects. Excellent optical performance Two Special Low Dispersion (SLD) glass elements are provided for effective compensation of color aberration, which is a common problem with super-wide angle lenses. Four pieces of hybrid aspherical lenses offer excellent correction for distortion as well as all types of aberration. This lens excellent optical performance makes it an ideal lens for Digital SLR Cameras as well as film SLR cameras. Super Multi Layer Coating It incorporates Super Multi Layer Coating to reduce the influence of harmful light caused by reflections from the digital image sensor. Minimum focusing distance of 33cm (13 in.) at all focal lengths It has a minimum focusing distance of 33cm (13 in.) at all focal lengths and a maximum magnification ratio of 1:4.4, which is very convenient for close-up photography. Zoom Lock Switch Mechanism This lens is also equipped with a zoom lock that eliminates Zoom Creep. This remarkably compact, high performance zoom le