Sep 15, 2024 · The Contax mount to focal plane distance is always quoted to be 34.85mm, although I can't figure out what feature of the Contax mount is used as a reference. Obviously there are two sets of bayonet taps on the Contax camera, one for normal lens and one for all other lenses. The Leica mount to focal plane distance is well known to be 28.80mm.