The Mir 37mm is a famous wide angle, branching into medium lens territory. It has a very long focus pull, so it is easy and fun to keep subjects in focus, because it feels evenly right. It is good at capturing actors blocking, moving from the forefront to the back of frame.
This lens has a native M42 mount, but has an EF adapter added. This lens covers full frame, Super 35mm and Micro 4/3.