Canon EF 50mm f/1.8 STMCanon EF 50mm f 1. 8 STM Compact and lightweight an outstanding walk around lens Canon's EF 50mm f 1. 8 STM is a great entry into the world of EOS prime lenses. With an 80mm effective focal length on APS C cameras, 50mm on full frame cameras, it's an excellent prime lens for portraits, action, 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