p.1 #1 · Swapping lens flanges for 6 bit coded third party
I have the following lenses and interested in swapping out the lens flanges for some third party ones that have 6 bit coding pits. I have been coding my own with a 3d printed tool and a uni marker, but I have to keep reapplying given there is no recess for the markings. It rubs off after a few uses.
Lenses:
1. Voigtländer 28mm f/2 Ultron II Vintage line
2. Zeiss Planar T* 2/50 ZM
3. Voigtländer 90mm f/2.8 APO-Skopar
They have the right options, except the one for the 50mm has a different bolt pattern and only 3 of the 4 screws would fit (which I am a little concerned about).
I'm also concerned about variability in the thickness of these and my own mount / whether that could cause issues with focus and alignment if off.
Has anyone used these or from another supplier?
I could drill my own pits but would prefer not to.
p.1 #2 · Swapping lens flanges for 6 bit coded third party
My inclination would be to remove the flange from my lens, carefully model it in CAD, add the pits and get it CNC machined in brass.
The slightest variation in thickness will ruin the RF alignment of the lens. I have a mitutoyo caliper I would trust to accurately measure the thickness.
I would probably 3D print a prototype first to make sure the pits align properly and the flange mounts securely.
robbrown99 wrote:
I have the following lenses and interested in swapping out the lens flanges for some third party ones that have 6 bit coding pits. I have been coding my own with a 3d printed tool and a uni marker, but I have to keep reapplying given there is no recess for the markings. It rubs off after a few uses.
Lenses:
1. Voigtländer 28mm f/2 Ultron II Vintage line
2. Zeiss Planar T* 2/50 ZM
3. Voigtländer 90mm f/2.8 APO-Skopar
They have the right options, except the one for the 50mm has a different bolt pattern and only 3 of the 4 screws would fit (which I am a little concerned about).
I'm also concerned about variability in the thickness of these and my own mount / whether that could cause issues with focus and alignment if off.
Has anyone used these or from another supplier?
I could drill my own pits but would prefer not to.
Steve Spencer Offline • • • • • • • Upload & Sell: On
p.1 #3 · Swapping lens flanges for 6 bit coded third party
robbrown99 wrote:
I have the following lenses and interested in swapping out the lens flanges for some third party ones that have 6 bit coding pits. I have been coding my own with a 3d printed tool and a uni marker, but I have to keep reapplying given there is no recess for the markings. It rubs off after a few uses.
Lenses:
1. Voigtländer 28mm f/2 Ultron II Vintage line
2. Zeiss Planar T* 2/50 ZM
3. Voigtländer 90mm f/2.8 APO-Skopar
They have the right options, except the one for the 50mm has a different bolt pattern and only 3 of the 4 screws would fit (which I am a little concerned about).
I'm also concerned about variability in the thickness of these and my own mount / whether that could cause issues with focus and alignment if off.
Has anyone used these or from another supplier?
I could drill my own pits but would prefer not to.
What do you use the 6-bit code for? Personally, when I used a Leica M camera I never wanted to use a 6-bit code for third party lenses because it applied the wrong profile for the lens. Sometimes the Leica lens profile was fairly close and wasn't too bad, but after awhile I found I was annoyed by the wrong profile being applied and quit using the codes for third party lenses.
p.1 #4 · Swapping lens flanges for 6 bit coded third party
6 bit coding non Leica lenses can be helping jsut to identify which lens your using. Many of the older lenses give exif data but don’t even have correction profiles so they stay native. Lightroom does have profiles for some third party lenses so you can apply those properly if you know which lenses actually took the picture. If you use only one lens and download right away that’s problem but if your switching lenses then you can you the 6 bit code to remind you what lens it was if it’s not actually a Leica lens
p.1 #5 · Swapping lens flanges for 6 bit coded third party
robbrown99 wrote:
I have the following lenses and interested in swapping out the lens flanges for some third party ones that have 6 bit coding pits. I have been coding my own with a 3d printed tool and a uni marker, but I have to keep reapplying given there is no recess for the markings. It rubs off after a few uses.
Lenses:
1. Voigtländer 28mm f/2 Ultron II Vintage line
2. Zeiss Planar T* 2/50 ZM
3. Voigtländer 90mm f/2.8 APO-Skopar
They have the right options, except the one for the 50mm has a different bolt pattern and only 3 of the 4 screws would fit (which I am a little concerned about).
I'm also concerned about variability in the thickness of these and my own mount / whether that could cause issues with focus and alignment if off.
Has anyone used these or from another supplier?
I could drill my own pits but would prefer not to.
Thanks...Show more →
I would we cautious with chasing the mount as well because any thickness change could be a big problem. However all the Voigtlander mounts I have, do have an indent in the center of the mount and retain 6 bit coding quite well.
Oct 07, 2026 at 06:31 AM
Steve Spencer Offline • • • • • • • Upload & Sell: On
p.1 #6 · Swapping lens flanges for 6 bit coded third party
misteracng wrote:
6 bit coding non Leica lenses can be helping jsut to identify which lens your using. Many of the older lenses give exif data but don’t even have correction profiles so they stay native. Lightroom does have profiles for some third party lenses so you can apply those properly if you know which lenses actually took the picture. If you use only one lens and download right away that’s problem but if your switching lenses then you can you the 6 bit code to remind you what lens it was if it’s not actually a Leica lens
I generally don't have a problem identifying which lens I was using, but YMMV. You can of course with some cameras use the camera menu to "identify" the lens, but I agree if you are going to do that the 6-bit code is easier. Which lenses don't apply any profile? It would be nice to have a list, so that people could use those 6-bit codes to "identify" all their third party lenses, for those that want to do that, without applying the wrong profile and then for lenses that have a Lightroom profile could apply that Adobe profile in post-processing.
p.1 #7 · Swapping lens flanges for 6 bit coded third party
Thanks folks for the responses.
Given the feedback I think I will pass on the idea of swapping out the mount for another due to alignment issues.
This is for identifying which focal length for me, and also for applying corrections in RawTherapee/ART. The lenses I have are very close in corrections to the 28 summicron, 50 summicron and 90 elmarit. The 28 Voigtlander is the one that needs correction the most (vignetting).
I am modifying the photo app I wrote to help apply the correct name of the lens easily as a comment, while retaining the Leica coded lens name for corrections.
I tried assigning manually in the camera, but every time I swapped lenses I forgot to switch it, which makes the situation worse. Not applying a lens was better.
I bought some Testors flat black paint so I will try that to see if the code holds up better.
While the voigtlanders do have a slight resess I didn't find it was actually helping to keep the paint / pen on. Maybe Testors will be better.
Of course there is always Leica lenses themselves but they are a little pricey for the equivalents.
I am quite surprised all the Chinese outfits don't just make a long deep pit which would help this. Technically not 6 bit (1 bit)
p.1 #8 · Swapping lens flanges for 6 bit coded third party
robbrown99 wrote:
Has anyone used these or from another supplier?
I've used his flanges. I want 6 bits coding because I change lenses often and with it sets the minimal shutter speed.
The flanges are perfect and Jin is a great guy, always helpful.
I would recommend trying at least and talking with him. If you cannot through EBay, message me here.
P.S: black paint choice is important, some are not detected. I'm using Tamiya Flat Black XF-1.
P.P.S: I know other methods to code my lenses and I've used them. Nothing come close to using Jin's flange: clean, reversible, etc.
