10-20mm F4-5.6 EX DC HSM lens allows enjoyment of super wide-angle photography and it is a very powerful tool for indoor shooting and landscape photography with digital SLR cameras. Wide angle of view (102.4 degrees at 10mm and 63.8 degrees at 20mm) offers the photographer greater freedom of expression. 3 Special Low Dispersion (SLD) glass elements are employed for effective compensation of color aberration, which is a common problem with super-wide angle lenses. One piece of glass mold and two hybrid aspherical lenses, offer excellent correction for distortion, as well as all types of aberration. This lens is equipped with an inner focusing system, and the models which are equipped with HSM system provide quiet, high speed autofocus shooting and also offer full time manual focusing. It has a minimum focusing distance of 24cm at all focal lengths. The non-rotating lens barrel perfectly suits the petal shaped lens hood. A circular polarizing filter can also be used conveniently. Angle of View - 102.4 - 63.8 degrees 6 Diaphragm Blades Minimum Aperture F22 Minimum Focusing Distance - 24cm/9.4 inches Maximum Magnification - 1 - 6.7 Filter Size - Diameter 77mm Lens Hood Petal Hood Dimensions - Diameter 83.5mm x Length 81mm, 3.3 x 3.2 inches Weight - 470 gram (16.6 ounces)