By reducing the distance from the rear of the lens to the focal plane and reducing the size of the image circle to match the size of the APS-C imaging sensor used in digital SLRs such as the EOS 20D camera and Digital Rebel camera,Canon's EF-S lenses reduce the size, weight and cost of wide-angle lenses for these cameras while at the same time producing high image quality with superb resolution and contrast at all focal lengths.
EF-S 18-55 3.5/5.6 USM
This is the USM version of the popular EF-S 18-55mm f/3.5-5.6 zoom lens that is available in kit form with the EOS 20D camera and Digital Rebel camera. Both lenses have an angle of view equivalent to a 29-88mm lens on a 35mm camera. Weighing in at just 6 oz. and measuring only 2.5 inches in length, the EF-S 18-55mm f/3.5-5.6 USM produces exceptional image quality in an ultra-compact package. The new lens accepts 58mm filters and features Canon's exclusive Micro USM II focusing motor technology for swift and silent AF.