Focal length: 50mm Maximum aperture: 1:1.8 Lens construction: 6 elements in 5 groups Diagonal angle of view: 46 degrees Focus adjustment: Overall linear extension system with Micromotor Closest focusing distance: 1.5 feet Filter size: 52mm Dimensions: 2.7 inches in diameter, 1.6 inches long Weight: 4.6 ounces