6 Bit Coding - Non Leica Lenses

[dgc]

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After a quick search on this site, I cannot find an explanation why the likes of Leica and Voigtlander do not bother with the 6 bit coding even though they both provide a recess in the area required.

Is it patent protected, but then surely the bayonet mount must be as well ?

 

David

[Guest]

...

 

Even some original Leica lenses are not coded by Leica, as they think it's not necessary, for example the M-Elmarit 2.8 - 135mm.

 

Others aren't coded, because the bayonet ring must be changed, but Leica can't do it, because a screw is just at that same place, where the coding must be fixed, for example the M-Summilux 1.4 - 35mm preaspherical.

 

Leica doesn't code lenses from other brands, as they never do any service on items not made by them.

 

Perhaps some other technicans with long experiences with Leica offer a six bit coding on those lenses.

Ask for example Will van Manen in the Netherlands, perhaps he can help you.

 

http://www.l-camera-forum.com/leica-forum/customer-forum/176538-6-bit-coding-van-manen.html

 

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[JakeStone]

After a quick search on this site, I cannot find an explanation why the likes of Leica and Voigtlander do not bother with the 6 bit coding even though they both provide a recess in the area required.

Is it patent protected, but then surely the bayonet mount must be as well ?

 

David

 

Leica provides exif data and in-camera lens correction for Leica lenses only.

So there is no official coding for any lenses of other brands. There might be best practice. or best guesses though. It would be very dangerous vor other brands to apply the coding and thus depending 100% on Leica in future concerning lens correction. What is currently good for a lens/camera combination, might not be good with a future Leica camera.

 

Even though you did not explicitly ask for it:

Many (or all?) new Voigtländer and Zeiss M lenses have a small flange (a tiny bit below, so that it will not be scratched when changing lenses) where a 6 but coding can be priveded using a black marker. No joke. Very easy.

 

br

Jacob

[StephenPatterson]

Is it patent protected, but then surely the bayonet mount must be as well ?

 

David

 

The patent on the M mount has long expired, but the 6 bit lens code is patented by Leica and cannot be used by Voigtlander, Zeiss or anyone else

[TomB_tx]

The patent on the M mount has long expired, but the 6 bit lens code is patented by Leica and cannot be used by Voigtlander, Zeiss or anyone else

I wonder if the Leica patent on the coding specifies that it is part of a camera lens, since there are 3rd-party providers of flanges with the coding pits already machined. Perhaps simply providing just the flange gets around the patent.

[dgc]

Leica provides exif data and in-camera lens correction for Leica lenses only.

So there is no official coding for any lenses of other brands. There might be best practice. or best guesses though. It would be very dangerous vor other brands to apply the coding and thus depending 100% on Leica in future concerning lens correction. What is currently good for a lens/camera combination, might not be good with a future Leica camera.

 

Even though you did not explicitly ask for it:

Many (or all?) new Voigtländer and Zeiss M lenses have a small flange (a tiny bit below, so that it will not be scratched when changing lenses) where a 6 but coding can be priveded using a black marker. No joke. Very easy.

 

If the reason is the patent, as Stephen suggests, then it is clear why other manufacturers do not bother coding. However, I always thought that Leica with its long term view on using the same mount etc and, I imagine, that the 6 bit coding is here for a while, that there would be minimal risk to the lens manufacturer in the future.

 

One thing though, when I manually choose the nearest compatible lens to my Zeiss 21mm, the SEM 21mm in the lens detection menu, it does provide in-camera correction, as there is a noticeable reduction in the red edge issue.

 

I would be interested to hear more about the black marker pen coding, I do not quite trust myself with a dremmel ! There is also a thread which indicates that Leica may consider a firmware update where the camera will recognise any 6 bit code and over-ride any manual input - I like the idea of that.

 

David

[StephenPatterson]

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I wonder if the Leica patent on the coding specifies that it is part of a camera lens, since there are 3rd-party providers of flanges with the coding pits already machined. Perhaps simply providing just the flange gets around the patent.

 

Many of these generic flanges are made here in China, where intellectual property rights are sometimes slightly abused.

 

The three different style flanges (for the three different frame lines sets) are provided with the coding pits, but obviously not painted as the Chinese manufacturers do not know what lens the flange will be coded as. If there were not so many codes I'm sure they would be painting these flanges.

 

I don't think Zeiss or Voigtlander would risk including the unpainted 6-bit pits as it would do little to help their sales and a loss in patent court could result in an expensive penalty.

 

I believe the 6-bit code was patented sometime around the introduction of the M8 in 2006, so you are looking at at least 20 years, not including any extensions that might be granted.

 

I have coded several lenses with the Match Technical code kit, which includes a template and marker pen. While this worked well on the M8 and M9 it does not work well (if at all) on the M240, due to a new and more selective sensor in the body.

 

This is much less of an issue than it was in the M8 days, when you could not manually select a lens code and had to apply a 6-bit code to have any in-camera corrections applied to 3rd party lenses. Of course with the M9 and M240 you must still remember to set the code, and return to automatic lens detection when mounting a Leica lens.

 

I'm not sure what you mean by "There is also a thread which indicates that Leica may consider a firmware update where the camera will recognise any 6 bit code and over-ride any manual input - I like the idea of that." Why would this be an advantage over the present system?

[dgc]

Stephen - you have sown seeds of doubt, which I cannot confirm as I do not have my M with me. My understanding is that when you manually set the lens type in the lens detection menu the camera records this in the EXIF data and sets any in-camera corrections. Once manually set, the camera only recognises this code, regardless of any change of lens, be it a Leica with 6 bit coding or not.

 

I like the idea that having manually set the closest Leica lens to my Zeiss 21mm in the lens detection menu, I would not have to enter any other settings if I was to change the lens with a lens with 6 bit coding, as the camera would automatically recognise the coding and over-ride the manual setting.

 

This would be useful where speed is paramount or should I just forget to change the setting ! Clearly, it would not help if you were changing to another Zeiss/ non-6 bit coded Leica lens etc.

 

I hope this makes sense.

 

David

Edited February 8, 2014 by dgc

[250swb]

I would be interested to hear more about the black marker pen coding, I do not quite trust myself with a dremmel !

 

Later Zeiss ZM and many newer CV lenses have a concentric groove machined on the face of the mounting flange, and it is there for no other purpose than to allow coding. A dab of matt black hobby paint in the groove is best, but some people make pens work (it depends very much on the brand). You only need to make a coding template

 

BoPhoto.com: M8 coder - simple manual handcoding of M lenses

 

and you are ready to code.

 

If however you have an older Leica lens that needs coding you can either buy replacement flanges via Ebay, these have the coding rebates already machined in, or use a Dremel. With common sense it is only a five minute job to swap flanges for anybody who can walk and chew gum at the same time. The simple pen system of marking the unmodified flange that worked with the M8 doesn't work with the M9 and M240, both really need a rebate or groove to take thicker opaque paint.

 

Steve

[StephenPatterson]

Stephen - you have sown seeds of doubt, which I cannot confirm as I do not have my M with me. My understanding is that when you manually set the lens type in the lens detection menu the camera records this in the EXIF data and sets any in-camera corrections. Once manually set, the camera only recognises this code, regardless of any change of lens, be it a Leica with 6 bit coding or not.

 

I like the idea that having manually set the closest Leica lens to my Zeiss 21mm in the lens detection menu, I would not have to enter any other settings if I was to change the lens with a lens with 6 bit coding, as the camera would automatically recognise the coding and over-ride the manual setting.

 

This would be useful where speed is paramount or should I just forget to change the setting ! Clearly, it would not help if you were changing to another Zeiss/ non-6 bit coded Leica lens etc.

 

I hope this makes sense.

 

David

 

OK, I understand now what you're getting at. Yes, it is a PITA to have to remember to change from a manual code to Automatic Lens Detection when mounting a Leica lens, but is a necessary step. I understand why you want to change it, but I'm not sure that Leica would want to go down this path of overriding a manual input in favor of an automatic setting. The present fiasco concerning AutoISO leads me to think that such a change in lens detection settings could lead to madness.

[jaapv]

Many of these generic flanges are made here in China, where intellectual property rights are sometimes slightly abused.

 

The three different style flanges (for the three different frame lines sets) are provided with the coding pits, but obviously not painted as the Chinese manufacturers do not know what lens the flange will be coded as. If there were not so many codes I'm sure they would be painting these flanges.

 

I don't think Zeiss or Voigtlander would risk including the unpainted 6-bit pits as it would do little to help their sales and a loss in patent court could result in an expensive penalty.

 

I believe the 6-bit code was patented sometime around the introduction of the M8 in 2006, so you are looking at at least 20 years, not including any extensions that might be granted.

 

I have coded several lenses with the Match Technical code kit, which includes a template and marker pen. While this worked well on the M8 and M9 it does not work well (if at all) on the M240, due to a new and more selective sensor in the body.

 

This is much less of an issue than it was in the M8 days, when you could not manually select a lens code and had to apply a 6-bit code to have any in-camera corrections applied to 3rd party lenses. Of course with the M9 and M240 you must still remember to set the code, and return to automatic lens detection when mounting a Leica lens.

 

I'm not sure what you mean by "There is also a thread which indicates that Leica may consider a firmware update where the camera will recognise any 6 bit code and over-ride any manual input - I like the idea of that." Why would this be an advantage over the present system?

The original patent is about using white and black spots to detect the lens, so just providing holes or grooves probably does not infringe the patent.

Having said that, I do not think Leica as ever enforced their rights, not even when a fellow German company, Novoflex, has been providing fully coded M to R adapters.

[StephenPatterson]

I do not think Leica as ever enforced their rights, not even when a fellow German company, Novoflex, has been providing fully coded M to R adapters.

 

Jaap, I believe that Leica would enforce their patents, as to not do so could potentially render them invalid. Why go to all the expense of obtaining a patent in the first place if you are not going to protect it?

 

As for the Novoflex M-R adapter, with the 6-bit code, it is clearly marked, "Under Licence from Leica Camera AG". I do not imagine that Leica is giving this licence for free to Novoflex.

 

Novoflex Adapter Leica R Objektive an Leica M Kameras - LEM/LER | eBay

Edited February 8, 2014 by StephenPatterson
Replaced "License" with "Licence" and learned something new...

[TomB_tx]

Jaap, I believe that Leica would enforce their patents, as to not do so could potentially render them invalid. Why go to all the expense of obtaining a patent in the first place if you are not going to protect it?

 

As for the Novoflex M-R adapter, with the 6-bit code, it is clearly marked, "Under Licence from Leica Camera AG". I do not imagine that Leica is giving this licence for free to Novoflex.

That's why big companies have to go after "the little guy" who infringes on a patent, even if his business is insignificant. They can't enforce selectively, so failing to defend loses the patent.

Novoflex provides the adapter already coded - not just with a place to apply the code, so that's likely why a license was needed. (Perhaps as part of the license they also make adapters for Leica brand?)

Zeiss and Voigtlander don't claim their M-mount lenses are intended for digital cameras so that complaints over digital issues can be defended. If they coded the lenses for digital the disclaimer would be weakened.

[LocalHero1953]

What corrections are applied in-camera to the dng file based on the lens selection? If I attach a non-Leica lens and manually select the nearest Leica equivalent in the menu, will it apply inappropriate corrections? Am I better off not making any manual lens selection at all?

[StephenPatterson]

What corrections are applied in-camera to the dng file based on the lens selection? If I attach a non-Leica lens and manually select the nearest Leica equivalent in the menu, will it apply inappropriate corrections? Am I better off not making any manual lens selection at all?

 

The corrections are almost exclusively for lenses 35mm and wider, but of course with all lenses the EXIF data is recorded making it easier to sort in Lightroom. For wide lenses the corrections mainly concern vignetting and magenta edge. Many members here (myself included) use manual lens codes with Zeiss and Voigtlander lenses, often with excellent results. For instance by coding the Voigtlander 12mm f/5.6 Heliar as a Leica 21mm Pre-ASPH (#11134) it substantially improves the image file and reduces or eliminates the need for post processing corrections, such as Cornerfix or Lightroom's flat field correction.

 

The best thing to do (other than searching the forum for past threads) is to just try a code and see if you like the results.

[nilca]

On 2/7/2014 at 6:57 AM, JakeStone said:

 

Leica provides exif data and in-camera lens correction for Leica lenses only.

So there is no official coding for any lenses of other brands. There might be best practice. or best guesses though. It would be very dangerous vor other brands to apply the coding and thus depending 100% on Leica in future concerning lens correction. What is currently good for a lens/camera combination, might not be good with a future Leica camera.

 

Even though you did not explicitly ask for it:

Many (or all?) new Voigtländer and Zeiss M lenses have a small flange (a tiny bit below, so that it will not be scratched when changing lenses) where a 6 but coding can be priveded using a black marker. No joke. Very easy.

 

br

Jacob

Agree with that; I have several Zeiss lenses where I just painted the 6-bit code within the recess on the flange and they've lasted for years, whilst changing lenses often. I suggest trying different code settings on your Zeiss wide-angle lenses (like the 18mm and 15mm) to get the best camera correction. It's not always the closest focal length match that works best, and it differs if you have different camera models (i.e. M9, M240, or M10). Fringe and vignetting [correction] is most noticeable for lenses that protrude deep into camera-box rather than the actual focal-length/width, because of the large angle to the corners. So, some old-design versions of Leica lenses, like the 28mm (III) receive more camera correction and these codes might produce more suitable correction for your non-Leica lenses than matching the focal-length.

BTW, If you want to keep track of which lenses you're using via Exif and perform your correction [elsewhere] post-process... there are some bit-codes that can only be accessed by changing the frame selector tab (on the flange.) One example: to access the Super-Elmar-M 18/3.8 bit code camera-correction (52=110100), your frame selector tab needs to be also set to: frame 50/75.