screwmounts

Screwmount refers to a type of lens mount commonly found on older Leica 35mm rangefinder cameras and their imitators. Developed by Leica, the screw mount, officially known as the Leica Thread Mount (LTM) or Leica Screw Mount (LSM), uses a standardized thread pitch for attaching lenses to the camera body. This system was introduced in 1932 with the Leica II camera and remained in production for many decades.

The primary characteristic of the screwmount system is its bayonet-like mechanism combined with a threaded barrel. The lens has a helical focusing ring and is screwed into the camera body. While many lenses were designed for specific focal lengths and apertures, the LTM mount allows for interchangeability among compatible cameras. Adaptors are widely available to mount LTM lenses onto modern digital cameras with different mount systems, making them popular among photographers seeking vintage optical quality. The mount itself is a significant part of photographic history, representing a robust and enduring design that influenced subsequent lens mount developments.