Top features: - Compact construction makes it ideal for travel photography - OS (Optical Stabiliser) technology allows the use of slower shutter speeds - Range of special elements ensure quality high definition images Compact construction makes it ideal for travel photographyThe 17-50 mm f/2.8 EX DC HSM has a compact and lightweight construction, making it an ideal choice for photography on the go. Covering a wide range of focal lengths from 17 mm, it can also be used for portraits, landscapes and general photography.Flare and ghosting is reduced by the Super Multi-Layer coating to provide sharp, high-contrast images throughout the entire zoom range. You can enjoy fast and quiet AF using the Hyper Sonic Motor, allowing you to take professional quality images.OS (Optical Stabiliser) technology allows the use of slower shutter speedsWith Sigma's unique OS (Optical Stabiliser) function you can use slower shutter speeds to achieve stable and clear shots. This makes handheld photography easier, offering you greater freedom and allowing you to capture images with ease.Range of special elements ensure quality high definition imagesThe 17-50 mm f/2.8 EX DC HSM features a range of special elements, including two FLD ("F" Low Dispersion) glass elements which compensate for colour aberration. Two glass mold elements and one hybrid aspherical lens help to correct for field curvature and astigmatism, enabling you to capture high-definition images.