Thanks for the clarification Frogfish.
It's also a shame the distance from lens to sensor in Leica cameras is so short, because none of their M mount lenses will work on "crop" and larger sensors from other brands...only on micro four thirds cameras. It might be possible for Leica to make versions of their M lenses that will mount on other brands, but they don't seem to want to. I guess they make enough profit from their partnership with Panasonic. The M lenses certainly are priced about as high or higher than all others. The one I would love to try is the 75mm f/2 Summicron. It looks like its price has come down a bit since last I checked, it's around $2700 now. It used to be $3700. The 50mm f/.95 Noctolux is still around $10k, I think.
I use a Fotodiox adapter (with "dandelion" focus confirmation chip) to mount a Nikon-mount lens to my Canon, the Cosina Voigtlander 58mm f/1.4. It is truly a magical lens. The adapter needed some tweaking to tighten it, and that damaged my admittedly cheap jeweler's screwdriver!
The bokeh highlights via this little Voigtlander may not be quite as smooth as the very best "normal" lenses in terms of bokeh...although they're smooth enough for me...but oh that sharpness!! Other than the 50mm Zeiss Makro Planar (which is an f/2 maximum lens, not 1.4)...I do believe this Voigtlander may be the absolute sharpest ~50mm lens there is. I've only used it on my crop camera, but I doubt the IQ drops off much even on a full frame, to the corners. One other quirk is that it won't meter light very accurately on my camera, with the aperture closed down. But it's possible any lens would do the same, with a manual aperture ring...since the only way to mimic light metering with automatic lenses to compare, would be to try to hold down the "depth of field preview" button while light metering. I doubt many DSLR's can do that, if any...nor would you want to, obviously.
The corners on the crop sensor via this lens, wide open (at least at or near infinity focus) stay absolutely sharp...with essentially zero lateral CA...and a small to normal amount of longitudinal (bokeh) CA. And there's very little vignetting wide open, if any...which is astounding and unheard of, to me. The color and contrast are up there near or with some of the very best, as well. Certainly the Canon 85mm f/1.2 "magic canonball" had more vignetting at f/2.2 than this Voigtlander has at f/1.4, on my camera. That 85mm also wasn't as sharp anywhere near the wide aperture end. By f/5.6 the "canonball" was a bit sharper than the Voigtlander is at the same aperture. But that's a huge, heavy, motor-focus driven $2000 lens!
Not many people know or care about this Voigtlander "Nokton", but it's a pleasure to use. Obviously it is "only" manual focus, and manual aperture. The build and feel are identical to other Zeiss lenses I have rented...and at much lower cost. It was the Photozone.de resolution test that ultimately convinced me to try this lens. I will probably never sell it.