Fx format medium telephoto lens with 85mm focal length 127 5mm when used with a nikon dx format slr fast f1 8 aperture enables beautifully smooth bokeh sharper shots in low light and a bright viewfinder image compatible with entry level digital slrs that do not have a built in autofocus motor swm silent wave motor for quiet and accurate autofocus two focus modes ma manual priority autofocus and m manual focus