Super-Angulon-M 21mm f/3.4

Introduced in 1963 as the successor to the earlier f/4 version, the Super-Angulon 21mm f/3.4 is one of the most famous true non-retrofocus symmetrical wide angles ever mounted on a 35mm rangefinder. Because the rear element sits millimeters from the film plane, it exhibits virtually zero geometric distortion and razor-sharp center resolution, rendering architectural lines and horizons with breathtaking purity.