Product description sigma objectif 50 500 mm f45 63 apo dg os hsm nikon manufacturer39s description a 10x high zoom ratio ultra telephoto zoom lens incorporating sigma39s original optical stabiliser function this lens covers a wide range of focal lengths from 50 mm 500 mm ultra telephoto the optical stabiliser function allows the use of shutter speeds approximately 4 stops slower than would otherwise be possible as compensation for camera shake is visable in the viewfinder the photographer c