The Nikon 50mm f/1.4 is a secret weapon for low-light photography. Far more important than a fast ISO speed is the ability to gather light, which this lens does extremely well.
One of the most widely used autofocus lenses in all of photography. Fast enough for shooting in just about any type of light. Distortion-free images with superb resolution and color rendition. Weighs only 9.0 ounces. An ideal first lens, perfect for full-length portraits, travel photography or any type of available-light shooting. Accepts 52mm filters; HR-2 lens hood.

Tech Specifications
Filter Size: 52mm
f/Stop Range: 2.8-22
Minimum Focus Distance: 8.4″ (20 cm)
Angle of View: 74 degrees
Groups/Elements: 8/8
Length: 1.8″
Maximum Diameter: 2.5″
Weight: 8.9 oz (250 g)
Some good info on the Nikon 50mm f1.4 here.