With its wide-angle view from 102.4 degrees it can produce striking images with exaggerated perspective. The maximum Aperture of F3.5 is ideal for indoor shooting and it enables photographers to emphasize the subject. Two ELD (Extraordinary Low Dispersion) glass elements and a SLD (Special Low Dispersion) glass element provide excellent correction of Color aberration. Four aspherical lenses provide correction for Distortion and allow compact and lightweight construction. The Super Multi-Layer coating reduces flare and ghosting. High image quality is assured throughout the entire Zoom range. The incorporation of HSM (Hyper-Sonic Motor) ensures a quiet and high-speed Auto focus as well as full-time manual focusing capability. This lens has a minimum focusing distance of 9.4 inches (24cm) throughout the entire zoom range and a maximum magnification ratio of 1:6.6. The lens design incorporates an inner focusing system which eliminates front lens rotation, making the lens particularly suitable for using the Petal-type hood and polarizing filter. The Petal-type hood blocks extraneous light and reduces internal reflection. -Unique to Sigma: Widest range with HSM -Super-Wide: 10-20 with maximum aperture of F3.5 throughout entire zoom range -High Image Quality: Two ELD (Extraordinary Low Dispersion) glass elements and a SLD (Special Low Dispersion) glass elements and Four Aspherical lenses -Includes: Petal-type Hood supplied -Specifications-Lens Construction: 13 Elements in 10 Groups-Angle of View: 102.4 - 63.8 degrees-Number of Diaphragm Blades: 7 Blades-Minimum Aperture: F22-Minimum Focusing Distance: 24cm / 9.4 in-Maximum Magnification: 1:6.6-Filter Size: Diameter 82mm-Lens Hood: Petal-type Hood-Dimensions: Diameter 87.3mm X Length 88.2mm; 3.4 in. X 3.5 in-Weight: 520g / 18.3 oz.