Samyang 21mm F1.4 ED AS UMC CS Lens - Sony E Mount (7714). Wide Angle Manual Focus Photo Lens for Mirrorless Cameras. Samyang Optics 21mm F1.4 ED AS UMC CS is a wide angle manual focus photo lens for mirrorless cameras with APS-C sensor sizes. With broad 21mm angle of view and 3 glass aspherical lenses, it provides an opportunity to experience the depth and breadth of image. Samyang 21mm F1.4 can be used for various purposes, such as exterior and interior landscapes and portraits.