Stepping motor delivers excellent autofocus with quiet performance.The optical design and stepping motor deliver smooth autofocus during video shooting. The lens design fully accommodates the Fast Hybrid AF of Sony E-mount cameras for super-fast autofocus functionality. Using face recognition AF results in consistent autofocusing on faces. even as the subjects move.Combines compactness with outstanding optical performanceThe SIGMA 16mm F1.4 DC DN | Contemporary features SIGMA's inner focus technologies. while lighter lens elements in the focus lens group make possible a more compact actuator. Moreover. this lens offers outstanding stability whether the photographer is shooting handheld or has the camera placed on a surface. Structurally. the lens features materials and parts that contribute to its compact. lightweight structure. In summary. this is an unprecedented lens that combines outstanding optical performance with exceptional portability and usability.Large lens hood (supplied) to keep out harmful raysThe lens hood cuts harmful rays that can negatively affect photographs while also minimizing reflectivity within the hood itself. The hood also features a rubber construction and a non-slip groove to make it easy to hold in a variety of shooting situations.High-precision. rugged brass bayonet mountThe brass mount combines high precision with rugged construction. Its treated surfaces and enhanced strength contribute to the exceptional durability of the lens.Mount with Dust and Splash Resistant StructureThe mount features a special sealing* for a dust and splash resistant structure to make the lens an excellent choice in a wide variety of conditions.*Except for Canon EF-M mountImage quality rivaling that of our Art line lensesWith 16 elements in 13 groups. the optical system features a multitude of high-tech and high-end components. including three FLD glass elements. two SLD glass elements. and two molded glass aspherical elements. This optical system minimizes optical aberrations and ensures outstanding resolution at wide-open aperture and throughout the aperture range. In particular. the two aspherical lens elements have ultra-high-precision surfaces polished to tolerances under 10 nanometers. minimizing the onion ring bokeh effect that some aspherical elements produce and ensuring clear image quality throughout the frame. In addition. the structure of the optical system gently bends light to minimize sagittal coma flare and deliver optimal optical performance from the center of the frame to the edges. The result is a smooth. round bokeh effect with ample light volume throughout the frame.Designed to minimize flare and ghostingFrom an early stage in the lens design process. flare and ghosting have been measured to establish an optical design resistant to strong incident light sources such as backlighting. SIGMA's Super Multi-Layer Coating reduces flare and ghosting to help photographers produce sharp and high contrast images even in backlit conditions. The included lens hood can be attached to block out extraneous light. which can have a negative effect on rendering performance.Rounded diaphragmThe 9-blade rounded diaphragm creates an attractive blur in the out-of-focus areas of the image.