From 300mm telephoto to 800mm ultra-telephoto this lens provides a constant fast maximum aperture and is optimized for digital SLR camerasThis lens covers the telephoto range from 300mm to the ultra-telephoto range up to 800mm. By continuously varying the angle of view from 8.2° to 3.1°, the lens takes a lot of the footwork out of picture composition.Lens coating reduces Ghost and FlareThe multi-layer lens coating and lens design re