Sony SAL-500F80 500mm f/8 Reflex Super Telephoto Lens for Sony Alpha Digital SLR Camera 500mm super telephoto lens with f/8 maximum aperture for Sony Alpha digital SLR camera World's only super telephoto reflex lens with autofocus capability for quick shot reactions Reflective optics eliminates the chromatic aberration to produce sharp, clear images Shutter speed exposure control; hold button locks autofocus for full creative control Measures 3.62 inches in diameter and 4.75 inches long; weighs 1 pound, 7 ounces