... blog post:
Modern production Leica M lenses have a 6 bit code engraved into their mount which is a series of black and white 'stripes' that tell a digital M camera body which lens is mounted on it. But...
![](https://image.jimcdn.com/app/cms/image/transf/dimension=421x10000:format=jpg/path/sc2cdead4efa54ea0/image/i4b4f4231f68816b2/version/1631801623/image.jpg)
Older Leica lenses that were made in the days of film camera do not, even versions of lenses that are still in production today but were manufactured in the pre-digital days, of course, don't either though their later digital era counterparts do.
Equally, any M lens acquired from a Leica competitor like Zeiss or Voigtlander will also be uncoded.
So, can you get such lenses 6-bit coded retrospectively? Well, the answer is yes and no. Leica maintain a long list of their lenses that can be retro-coded by their service department which may be found here. As may be expected this service isn't cheap, excludes quite a few lenses which cannot be converted for technical reasons and of course they won't do this for rival makers lenses.
![Zeiss 35mm f/2.8 ZM Biogon with 6-Bit coding by Skyllaney Opto-Mechanics - photo courtesy of Skyllaney](https://image.jimcdn.com/app/cms/image/transf/dimension=393x10000:format=jpg/path/sc2cdead4efa54ea0/image/i78eec9ae28bcb65a/version/1631794418/image.jpg)
Which leaves us where? Well one solution for owners of non Leica M-mount lenses, or indeed those seeking a more cost friendly option for their Leica lenses, is provided by the good people at Skyllaney Opto-Mechanics.
They can add 6 bit coding to most Zeiss ZM, Voigtlander VM and Leica M lenses using their specially designed coding machine. All the work they have carried out for me so far has been excellent and I currently have three lenses (one Leica, one Voigtlander and one Zeiss as it happens) away with them being coded, as I type this.
Result!