50 millimeter focal length and maximum aperture of f/1.8 Great for portraits, action, and nighttime photography; Angle of view (horizontal, vertical, diagonal): 40º, 27º,46º Minimum focusing distance of 1.15 feet (0.35 meter) and a maximum magnification of 0.21x Stepping motor (STM) delivers near silent, continuous move Servo AF for movies and smooth AF for stills 80 millimetre effective focal length on APS C cameras, 50 millimetre on full frame cameras. Lens construction: 6 elements in 5 groups