A professional level supertelephoto lens with a high speed Supersonic Wave Motor that offers amazingly fast autofocusing and 3 aspherical elements to eliminate field curvature and chromatic aberration. The 300mm f/2.8 has ‘focus lock’ buttons, two manual focus modes (with and without autofocus assist), as well as a focus range limiter to allow every aid to accurately focus. It also has a 9 blade circular aperture to provide smooth out-of-focus blur. All-in-all, the best supertelephoto available for Sony dSLR’s.