sigma 10-20mm f 4-5 .6 ex dc hsm lens for canon digital slr cameras
designed exclusively for canon digital slr cameras the ultra-wide-angle 10-20mm offers a view from 102.4 to 63.8 degrees making it ideal for landscape photography and other vast applications . the lens is distinguished by its three special low dispersion sld glass elements which effectively compensate for color aberration and its aspherical lenses which provide maximum correction for distortion and various aberrations . as a result the lens produces an extremely high image quality throughout the entire zoom range . the hsm-equipped models meanwhile produce fast autofocus af speeds and quiet shooting while still letting you perform full-time manual focus . other details include a minimum focusing distance of 9.4 inches at all focal lengths and an integral petal-type hood to block out extraneous light . lens elements and coating the new multilayer lens coating and lens design reduce flare and ghost -- a common problem with digital cameras -- while also creating an optimal color balance throughout the entire zoom range . at the same time the lens offers three sld glass elements that effectively compensate for color aberration along with a piece of glass mold and two hybrid aspherical lenses that offer excellent correction for distortion and all types of aberration . inner focusing system and hsm the lens incorporates an internal focusing system that eliminates front lens rotation letting you use a petal-type hood to protect from additional glare . and models equipped with a hyper-sonic motor hsm produce silent high-speed autofocus and full-time manual focus for sigma canon and nikon d-mount lenses . best consumer lens the sigma 10-20mm lens is so respected that it was named the best consumer lens in europe 2006 by the technical image press association tipa a collection of 31 publications from 12 countries . according to tipa the 10-20mm lens offers a versatile range of wide-angle focal lengths a good optical performance and a budget price making it an excellent investment for owners of dslrs with aps-c format sensors . its sharpness remains constant throughout the zoom range and its compact size makes it an ideal companion for shooting travel landscapes or architectural subjects . lens construction 14 elements in 10 groups angle of view 102.4 to 63.8 degrees number of diaphragm blades 6 minimum aperture f 22 minimum focusing distance 9.4 inches maximum magnification 1 6.7 filter size 77mm dimensions 3.3 inches in diameter and 3.2 inches long weight 16.4 ounces