The Samyang mm f/2.148 IF ED UMC Aspherical is an ultra wide angle prime lens produced by Samyang Optics for the 35 mmfilm format. Released in 2009 as a replacement for the short-lived Samyang 14mm f/2.8 IF ED MC Aspherical, this manual focus-only lens has an aperture ring which manually adjusts the aperture with half-stop clicks.