Voigtlander APO 6 bit coding service

[o2mpx]

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Does anyone know if there’s a service shop that performs 6 bit coding service for Voigtlander VM lenses?

Understand it could be done with paint coding, but was looking for a less DIY setup. 

[Gobert]

I don’t understand. Why would you want that. Bit coding is specifically for Leica lenses.

[Photoworks]

What are you going to code them to? a leica lens?

[o2mpx]

Voigtlander makes Leica M mount lenses. The ones of interest are APO 50mm and 35mm. Both don’t have 6 but coding, albeit there’s lots of information how to apply in a DIY manner.
 

There’s even a seller on eBay selling mounts with 6 bit coding but requiring a shim. 
 

Net is looking for a shop that might provide 6 bit coding mounts similar to several that do same for non coded Leica lenses. 

[Photoworks]

The reason I asked it is that on coded lenses Leica applies a few image corrections. You don't want to apply correction to your lens from a different lens, I will result in unpleasant results.

I don't think the apo lenses need any correction. better off selecting it from the menu.

[lct]

Most if not all my CV and ZM lenses are hand coded. Not difficult a DIY work at all. Please feel free to ask if you need any help.

[ianforber]

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I only have one non-Leica lens - a CV 35mm f1.5 and I have selected the profile of a 35mm Summilux from the camera menu. I did so because my testing showed that it reduced vignetting. Aside from that, I can’t discern any difference between using it as a non-coded lens or a pretend Summilux and produces very pleasant results. If I had more than one non-coded lens, I could see the advantage of having them 6-bit coded so that I wouldn’t need to choose the appropriate pretend M lens profile every time I mounted that lens. I have heard that some lenses benefit more than others by using a profile that reduces distortion etc  

That’s a long way of saying that I too would use a professional coding service. I made a complete hash of hand coding so gave up.  I think there are threads here that mention a guy in the US ho does this but has a waiting list of several years. 

it’s not the end of the world though. Pretty much everything can be corrected quickly in post-processing so all you’re losing is the EXIF data. 

[lct]

Some M cameras need to know the ID or at least the focal length of M lenses to work properly under lens detection auto or to calculate shutter speeds in auto iso mode. Better have those lenses coded or hand-coded for this simple reason. 

[Photoworks]

Leica's approach is: if 6bit is detected you get some correction. Vignetting correction is still moderate, the camera still can't tell what f-stop you are shooting in. Color correction is also performed on some lenses where you get a change of color from the center to the corner. Some lenses get a CA correction.

If No 6bit is detected: you can pick a lens from the menu, there is EXIF data written, but no other correction. EVF can benefit from the information for stabilizing the image.
you can make your correction in post. This is a positive option because you don't apply lens corrections that are made specifically for one lens.
If you fool your camera with added 6bit you may apply an over-correction that can not be reversed. this applies mostly to wide-angle lenses in my testing.

 

 

[Photoworks]

@lct

I know you don't care or see the difference with your lenses or on your images. as we had a long discussion before about it on this forum. 
People should know about the risk and benefits of coding lenses to a different Leica lens.

[lct]

8 minutes ago, Photoworks said:

@lct

I know you don't care or see the difference with your lenses or on your images. as we had a long discussion before about it on this forum. 
People should know about the risk and benefits of coding lenses to a different Leica lens.

Not sure i recall when this discussion took place but i did not change my mind i must say, rather the opposite sorry... 

[pedaes]

22 minutes ago, Photoworks said:

but no other correction

What is your evidence for this statement?

In his non-Leica M-mount lens tests, Sean Reid (Reid Reviews - subscription site) shows vignetting and other differences with and without a Leica lens selected in the Menu.

Corrections are minimal at 50mm and longer, and mostly benefit the wider angle lenses.

[Gregm61]

Fortunately M lenses are not made to the same (lack of) optical correction as so many other makers, intending corrections be applied from the start.

Shot raw and not applying any corrections, or just those I do manually in ACR works just fine and my main reason for using only 6 bit coded lenses is the convenience of having all images accurately tagged with the actual lens used.

I’ve used my M262 with sets of uncoded lenses and often never thought to manually change the setting when changing lenses. It’s a complete and utter PITA to have to do so, to the point I turned the function off and wound up with large numbers of images with “uncoded” in the lens section rather than show an incorrect focal length.

Been a long time since I bought an uncoded Leica lens or other brand and that time is only going to continue to extend going forward. Bought my last uncoded M-mount lens long ago. Not even these new generation Cosina-posing-as-Voigtlander lenses tempt me.

[lct]

•

Edited May 30, 2023 by lct

[lct]

2 hours ago, pedaes said:

In his non-Leica M-mount lens tests, Sean Reid (Reid Reviews - subscription site) shows vignetting and other differences with and without a Leica lens selected in the Menu.

Corrections are minimal at 50mm and longer, and mostly benefit the wider angle lenses.

Indeed, suffice it to use an uncoded UWA lens to check this. M11 + ZM 21/4.5 resp. uncoded and coded as Elmarit 21/2.8 through lens detection manual (OoC jpegs). 

Welcome, dear visitor! As registered member you'd see an image here…

Simply register for free here – We are always happy to welcome new members!

 

[lct]

Same effect when the lens is hand-coded. M11 + ZM 21/4.5 resp. lens detection off and hand coded as Elmarit 21/2.8 (OoC jpegs).

Welcome, dear visitor! As registered member you'd see an image here…

Simply register for free here – We are always happy to welcome new members!

 

[lct]

On 5/30/2023 at 2:39 PM, Photoworks said:

Leica's approach is: [...] If No 6bit is detected: you can pick a lens from the menu, there is EXIF data written, but no other correction. [...]

Different experience here. If no 6-bit coding is detected, i can indeed pick a lens from the menu and there is exif data written but also both vignetting and color shifts are adjusted accordingly.