Archived posting to the Leica Users Group, 1996/11/14
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]That's a frame line pre-select lever. It allows you to pre-view frame line from various focal length lenses. M4 I think has 35mm, 50mm, 90mm and perhaps 135mm (?) frame lines. I'm not sure about the 135 lines. Someone more knowledgable than myself will chime in if I'm wrong.