Large aperture standard zoom lens with a minimum focal length of 17mm, designed exclusively for digital SLR cameras and incorporating Sigma's original OS (Optical Stabilizer), the OS function offers the use of shutter speeds approximately 4 stops slower than would otherwise be possible. The lens has a compact construction with an overall length of 91.8mm. This compact and lightweight construction makes the lens ideal for travel photography. Two FLD (“F” Low Dispersion) glass elements, two glass mold and one hybrid aspherical lens provide excellent correction for all types of aberrations. This lens has superior peripheral brightness and provides sharp and high contrast images even at the maximum apertures. The incorporation of HSM (Hyper Sonic Motor) provides fast and quiet AF.