Offering excellent image quality in an ultra-compact design, this Sigma 17mm f/4 DG DN Contemporary Lens is an ultra-wide-angle prime for Sony E-mount cameras. Designed with an inner focusing system and stepping motor, this lens provides fast and reliable autofocus for both stills and video. The optical design produces high sharpness and clarity throughout the aperture range, and individual elements feature a super multilayered coating to suppress flare and ghosting for greater contrast and color fidelity when working in strong lighting conditions. Additionally, the lens offers a minimum focusing distance of just 4.7″, which allows for unique close-up photographs with expansive backgrounds, making it particularly appealing to vloggers, hikers, landscape photographers, and more.Compact, ultra-wide prime lens designed for full-frame Sony E-mount mirrorless cameras that can also be used on APS-C models where it provides a 25.5mm equivalent focal length.Inner focus system with stepping motor for fast, reliable AF for both still and video use.Equipped with an aperture ring, focus mode switch, and a knurled manual focus ring for a pleasing tactile experience.Minimum focusing distance of 4.7″ allows for unique close-up photographs with expansive backgrounds, making it particularly appealing to vloggers, hikers, landscape photographers, and more.Compatible with AF assist function and lens aberration correction on supported cameras.Dust and splash-resistant construction with a brass bayonet mount for ensured accuracy and durability.