Leica 50mm F1 Noctilux High Performance Lens of Extreme Speed for Exceptional Optical Results. The Noctilux gathers more light than the Human Eye.  Pictures will show more detail than when actually viewing the scene. The Noctilux performs Superbly throughout the Aperture range and can be used as a normal lens. Can be Handheld at Night Time after the Sun has Set.  Great for Street Scenes, Night Scenics and Sunsets/Sunrises. 7 Elements in 6 Groups Filter Size is 60mm Aperture Range from F1 to F16 with clicks at Half Stops Focuses 1 Meter to Infinity Only comes in Black Built in Telescopic Hood Made from Solid Bronze with Special Optical Glass (heavy) The Fastest Lens in the World