The Sony 16-50mm f/3.5-5.6 OSS Alpha E-mount Retractable Zoom Lens is a retractable zoom lens with a focal length range of 24-75mm in the 35mm format equivalency. It covers shooting lengths from true wide angle to standard portrait length and is a great day-to-day type lens/ especially since its unique retractability keeps it very compact. When powered on/ the lens expands/ but in its off position the lens is only 1.2" (30mm) which will fit in your pocket. When expanded/ it has a surprisingly large zoom range and access to its dual-function control ring for manual focus and zooming. Its Power Zoom capability in AF mode and Internal Stepping Motor provide/ fast/ smooth and quiet autofocus which is helpful when shooting video with this lens.<br />The lens is a Sony E-mount lens that is compatible not only with the NEX cameras but also with the NEX Handycam Camcorders. The built-in Optical SteadyShot image stabilization system reduces the effect of camera shake which is particularly problematic when tracking moving subjects in video or shooting photos in low-light. The OSS provides approximately 4-stops of shutter speed correction to help create blur-free images no matter the shooting conditions. Four Aspherical elements and one ED element correct for curved perspective at wide-angle lengths and chromatic aberration at telephoto lengths to provide sharp/ high contrast imaging across the entire frame.<br />