This 70-200mm f/2.8 VR is one of the two lenses used by most professional photographers every day.Fast f/2.8 speed for low light, soft backgrounds and action-stopping shutter speeds. Fast, quiet AF with a silent wave motor. You won't scare sensitive subjects as other AF lenses might. Three AF-Lock buttons to lock focus when pressed and held. These are extremely handy once you learn to use them.