Rangefinder Coupling on Leica M7, M9: CZJ M39, Leica Summ5cm

[stevesurf]

Hi folks, I know I know this is another of endless and boring RF coupling questions.

Just to get the humor out of the way, a search result here only came up with this:

[calvin83]

#1 Will a Leitz Summar 5cm f/2 M39 couple to my Leica M7 or M9 with any M39 to M Mount adapter?

Yes. Assume the camera/lens are properly adjusted and the adapter have the correct thickness.

#2 Will a Carl Zeiss Jena Biotar 58 M39 also allow the rangefinder patch focusing to my Leica M7 or M9 with any M39 to M Mount adapter?

No. Unless your Biotar 58 is converted to L39 with a coupling cam adjusted to fit your lens.

[stevesurf]

[calvin83]

You need a 50mm one with an opening to accommodate the focusing tab, as indicated below.