a quick explanation of the Leica M rangefinder mechanism

Please consider that Leica M camera and lens tolerances exist on a continuum, not as absolutes!
This means that if your camera (within tolerance!) is at one end of the continuum, and your lens (also within tolerance!) is toward the opposite end of the Continuum of Tolerance, critical focus may not be possible (e.g., "back-" or "front-focus").

[@Residew]

Thank you for the info!

[@thatsreallyamoon]

Great explanation, was curious how these lenses attached to the viewfinder system.