A portrait-length prime featuring a compact design, the YN 50mm f/1.8S DA DSM from Yongnuo is a 75mm-equivalent lens designed for APS-C-format Sony E-mount mirrorless cameras. The lens's bright f/1.8 design suits working in low-light conditions and also enables increased control over depth of field for isolating subject matter. The optical design incorporates one low dispersion element, which helps to reduce chromatic aberrations and color fringing, and a nano multi-layer coating has been applied to suppress flare and ghosting for improved contrast in strong lighting conditions. Balancing the optics is a DSM autofocus system, which promotes fast and quiet focusing performance to suit both photo and video applications.