The FE 70-200mm F2.8 GM OSS delivers superb Image quality throughout the zoom range at all focusing distances with two aspherical elements and one XA (extreme aspherical) element to ensure high resolution throughout the image area. Two ED (extra-low dispersion) glass elements, two Super ED glass elements and one ED aspherical element to minimize chromatic aberration while Sony's Nano AR (anti-reflective) Coating II subdues flare and ghosting. For additional reach, high-performance 1.4x and 2x teleconverters are available (sold separately). Four of Sony's original XD (Extreme Dynamic) Linear Motors deliver high thrust efficiency that boosts AF speed by up to 4x compared to the previous model for fast, precise continuous autofocus and tracking for stills and movies. AF tracking while zooming is improved by approx. 30% which greatly increase chances of getting the shot even with subjects moving rapidly towards the lens. Designed with movie magic in mind and the latest lens technology to reduce focus breathing, focus shift when zooming and axis shift when zooming. The XD Linear Motors and a new aperture drive unit contribute to quiet operation and independent control rings for focus, zoom and iris, with a click on/off switch for the aperture ring, make this lens ideal for movie shooting. Sony?s Linear Response MF feature ensures responsive and repeatable direct manual focus control. This lens offers outstanding optical quality and autofocus in the world?s lightest* 70-200mm F2.8 zoom lens. XD Linear Motors and magnesium alloy barrel components result in an overall weight of just 2.3 lb. (1045 grams); approx. 29% lighter than the previous model. Advanced design improves balance, while a constant barrel length further contributes to easy, agile handling.