Voigtlander M-Bayonet Adapter Ring for 28mm & 90mm Screw-Mount Lenses (Mounts on M-Bayonet Cameras)

Comments about Voigtlander M-Bayonet Adapter Ring for 28/90mm:

I bought both the 28/90 and 35/135 adaptor rings to fit 90mm and 35mm Voigtlander lenses I've been using with a Voigtlaner Bessa R camera to a Leica M9.

These bring up correct bright lines in the finder, however they don't have 6 bit coding so you need to use the manual lens selection function on the camera to correctly record the focal length in the EXIF data.

I also have a 21mm Voigtlander lens which I've tried on the M9; there is a well reported issue with magenta colour shift on the left side of the image using the 21mm Voigtlander on the M9. With the optimal 21mm lens selected from the menu on the M9 this can minimised but not eliminated.

Comments about Voigtlander M-Bayonet Adapter Ring for 28/90mm:

This is an adaptor ring for attaching Leica screw mount (so-called L mount) lenses to Leica M mount bodies. The 28/90 mm version of the adaptor ring activates the 28/90 mm bright frame in the camera's range finder. (On my Leica M4, the whole finder corresponds to 28 mm, so there is no bright finder for that focal length.)

Other manufacturers offer adaptors having the same function. The obvious difference is cost -- the expensive ones cost 5 times that of the cheapest. The qualitative difference is subtle. Once you hold the adaptor in your hand, observe it closely, and attach it to your lens first and then to the camera, you will see that the better adaptors are built much more precisely and carefully. The result is aesthetically pleasing.

In order to attach the mount as close to the lens as possible (flush to the lens mount base), Cosina Voigtlander made their adaptor ring very thin yet strong. The ring can be attached by hand, but for firmly attaching and detaching, you use the 3 notches around the ring's circumference. The plastic lens cap and body cap that come with adaptor (nice accessories I didn't expect) have 3 male molded notches that you can use to tighten and loosen the ring.