Sigma 18-50mm f/2.8 EX DC SLD ELD Aspherical Macro Lens for Canon Digital SLR Cameras Large aperture of f2.8 throughout the entire zoom range Minimum focusing distance of 8" & a maximum magnification factor of 1 to 3 Aspherical lenses offer compact and lightweight construction SLD and ELD glasses offer excellent correction of color aberrations Designed to fit Canon digital SLR cameras