The tremendous speed of this lens marks one of the numerous optical breakthroughs for Nikon. Its value for available-light photography is self-evident. Equally important, the shallow depth-of-field at F/2 means easier and more positive focusing under all light conditions. All glass-air surfaces of the 28mm F/2 are multi-layer-coated, a special process whose superior effectiveness in improving light transmission and contrast and reducing flare is considered a milestone in the development of high-speed quality optics. Another special feature is the independent rear lens group movement which produces markedly improved image quality at close distances.