With an 80mm effective focal-length on APS-C cameras, 50mm on full-frame cameras, the Canon's EF 50mm f/1.8 STM lens is an excellent prime lens for portraits, action, and even nighttime photography. Its bright maximum aperture of f/1.8 helps it not only to excel in low light, but also to capture gorgeous, sharp images and movies with beautiful background blur thanks to its circular 7-blade design. An updated lens arrangement with new lens coatings helps render images with excellent color balance, plus minimized ghosting and flare. Performance is brilliant, with a stepping motor (gear-type STM) to deliver near silent, continuous Movie Servo AF for movies plus speedy, smooth AF for stills. It's a fixed focal length gem.