EF-S 10-22mm f/3.5-4.5 USM This exciting new zoom lens provides ultra wide-angle coverage to the EOS 20D and Digital Rebel shooter. Equivalent to a 16-35mm zoom, it offers excellent performance and optics designed from the ground-up for digital SLR use. Three Aspherical lens elements, plus a Super-UD element, assure image quality. Its ring-type USM means fast and silent AF along with full-time manual focus. It focuses as close as 9.5 inches. Features Excellent optical quality and true wide-angle coverage with select digital SLRs Superior AF performance and speed, with full-time manual focus by simply turning ring Close-focusing to 9.5 inches -- fill the frame with subjects as small as 3.6 x 5.4 inches Relatively compact size and light weight for an ultra-wide zoom lens Inner focusing system (no front element rotation); length doesn't change if zoomed Circular aperture design -- natural highlights, even stopped down two stops Electronic diaphragm -- manually-set apertures stay constant from f/4.5 thru f/22 EF-S lens mount -- exclusively for EOS 20D and Digital Rebel bodies Lens Focal Length & Maximum Aperture 10 - 22mm; 1:3.5-4.5 Lens Construction 13 elements in 10 groups Diagonal Angle of View 107° 30' - 63° 30' Focus Adjustment Inner focusing system, with focusing cam Closest Focusing Distance 0.24m / 0.79 ft. Zoom System Ring USM Filter Size 77mm Max. Diameter x Length, Weight 3.3" x 3.5", 13.6 oz. / 83.5 x 89.8mm, 385g