The Canon EF50MM F/1.8 STM Lens for Canon DSLR Camera has an 80 mm effective focal-length on APS-C cameras and 50mm on full-frame cameras. It is an ideal prime lens for portraits, action and even night-time photography. Its bright maximum aperture of f/1.8 helps you to capture sharp images and movies with beautiful background blur thanks to its circular 7-blade design. This unit's stepping motor (gear-type STM) delivers near silent, continuous Movie Servo AF for movies plus speedy, smooth AF for stills. The all new exterior with enhanced focus ring placement allows easy manual focus adjustments.