LTM (LeicaThread Mount) to M-mount Adapter Adventure II

I finally received a Kipon LTM to M mount adapter with 6-bit coding. Everything goes together fine, however, there is a new wrinkle in the process.

Having an adapter that incorporates 6-bit coding alieveates the issue that required application of gaffer tape show in this blog post. You can see here the physical difference between an LTM adapter that has 6-bit coding and one that doesn’t incorporate it.

The segment that is cut out, illustrated by the RED annotations. On the Kipon adapter (right) the cut out is smaller to allow machining of the 6-bit coding on the back (camera) side of the adapter.
Shown here, the Beschoi adapter lying on top of the Kipon adapter. The 6-bit coding section on the Kippon is circled in RED. You can see the Beschoi adapter is machined away in that area.

This minor appearing difference is all the difference in the world if you are using a Leica with 6-bit coding.

The issue now is the fit of the adapter. Illustrated below the Beschoi aligns the mounted LTM lens pretty well with the camera body. On the other hand the Kipon has a good bit of misalignment.

Voigtlander 21mm f/4 Color Skopar mounted on M10-P using the Beschoi LTM – M adapter. You can see the RED mark emphasizing the alignment between the lens and the camera body. Pretty good, acceptable, I’d say
Same lens and camera with the Kipon LTM – M adapter. The RED marks help illustrate the amount of misalignment between the lens and the camera body.

The question is whether this mis-alignment is important or not. Based on the way that the focusing mechanism in the lens moves the rangefinder follower in the camera, this has no effect of focusing.

What causes the mis-alignment?

I measured the flange thickness of each LTM mount. By flange, I mean the part of the adapter that sits between the lens and M-mount on the camera body. The Beshoi is .05mm thinner than the Kippon. This is enough to change the alignment at assembly with the camera.

This saga, which in online forums is often trivialized “just get an LTM adapter” is much more trouble than you’d expect.

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