What does the M10 do with uncoded lenses?

[BradS]

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If one mounts an old, non-six bit coded lens on an M10, turns on the power and starts taking photos (without changing any menu items), what does the camera do?

In other words, what does the six-bit code do? What does one get by having a lens coded?

 

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[jdlaing]

Corrections for vignetting, color cast and exif lens identification.

[jdlaing]

And you can manually select an uncoded lens in the menus.

[GFW2-SCUSA]

I use both coded and uncoded Leica lens. Often I forget to put in the info then using uncoded lenses and shoot away. As far as the ultimate image, I can't see I missed anything. In my opinion the coding isn't very important for image quality. The meta data doesn't have the right lens in it, but that doesn't mean much to me. I am not a pixie-peeper and am not fussy about small things.  I've been using Leica since the early 1960's (Nikon, Hasselblad and others also) and love the Leica since I worry the least abut using it. It is a simple took that doesn't need to be fussed with, just used and enjoyed.  

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[AndreasG]

vor einer Stunde schrieb GFW2-SCUSA:

I use both coded and uncoded Leica lens.

So do I with the M10-D, which does not allow a manual lens selection via menu. The quality of the photos made with uncoded lenses is in principle the same, in case of some vignetting with uncoded wide angle lenses, e.g., 28mm and shorter, I remove the vignetting with a mouse click in PP. Color cast never was a problem., down to 21 and 18mm lenses. EXIF data I do not miss at all, therefore I decided already several years ago not to spend money for the 6-bit coding.

[graphlex]

I also use an M10D. My only uncoded lens is a 1982 75mm Summilux.  I don’t intend to have it coded, mainly because I’m happy with the focus calibration and don’t want to risk messing it up. I don’t notice any color casts or vignetting.  

Still, I’m a bit surprised that LR doesn’t offer up a profile, but it doesn’t seem to matter.

[Almizilero]

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Whenever I use an uncoded lens on the M10, it shows up as R-Adapter in the menu and later in post. That seems to be the default for uncoded lenses. I coded most of my lenses with a sharpie just for the focal lenght EXIF info, didn't notice any difference besides that (shooting RAW). 

[Al Brown]

As far as I know on M10 it jumps to the last lens you set up manual coding to. It has one memorized and goes to that coding when an uncoded lens is mounted (unles the setting is set ot OFF), so if all your lenses are coded and one is not coded you are still (by default) good, providing you at some point selected that lens in the menu when it was mounted.

Edited July 24, 2023 by Al Brown

[adan]

On 7/23/2023 at 5:22 PM, BradS said:

If one mounts an old, non-six bit coded lens on an M10, turns on the power and starts taking photos (without changing any menu items), what does the camera do?

In other words, what does the six-bit code do? What does one get by having a lens coded?

Frankly, I cannot remember what the "default behavior" for a brand-new M10 straight from the box is. Its menus may not yet be set for any particular lens. But as soon as you set one, the menu appears to select others, forever. In any event - the camera will take photos immediately. Push the shutter button, and the camera will not care what is mounted.

What does the code do? Automatically lets the camera's CPU know and record which lens is mounted, without any user effort required.

That does at least six things.
1) Let the camera know the focal length, which can be used to adjust the programming for the camera choosing Auto-ISO and shutter speed, according to the old formula for sharp hand-held photographs (shutter speed = 1/f - or 1/30th with a 28mm lens and 1/90th with a 90mm lens). With options to use 1/2x or 1/4x the focal length (i.e. 28mm > 1/60th or 1/125th instead of 1/30th)
2) Let the camera know the maximum aperture available.
3) Let the camera know the exact version and optical formula used, which can affect the following....
4) Let the camera know how much "digital" vignetting to expect, and correct for (a problem for compact M wide-angles lenses <50mm on digital sensors).
5) Let the camera know what "digital" color vignetting to correct for
6) Let the camera write the lens that was used for the image to the metadata/EXIF data, so that when editing you can see for yourself which lens you used, even 5-10 years from now. And in some cases apply corrections in post processing for distortion.

4) and 5) were Leica's primary reason for introducing the 6-bit coding in 2006 (with the M8). Digital sensors are simply different from film (flat textured silicon with limited ability to detact light from all angles vs. a thick gelatin coating that can be exposed from all angles).

Not everyone or every lens will need all of this data all the time - but it comes as a package when the lens is coded.

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With lenses 50mm and longer, the coding is less critical for clean color and other vignetting removal, but still has its functions.

What happens if you use an uncoded lens?

Again, not a lot if the lens is longer than 50mm - except that the camera will not necessarily correctly choosing an exposure time and Auto-ISO to reduce apparent camera shake. Or record accurate lens data to go with the picture.

Wider lenses will start to show the vignetting/color issues in the picture corners as they get wider. Some superwide M lenses are not compatable with or supported by Leica for color digital at all (although that improves slowly with each new digital Leica camera model). The very compact 21mm Super-Angulons from the 1960s; the Zeiss Hologon 15mm; and the Voigtlander 15mm lenses v. 1 and 2. You will get color bands or fringes of pink or cyan on the sides of a horizontal picture with those lenses.

If you want the accurate EXIF data and the corrections, you can take the time to enter the lens used manually in the camera menu. with every lens change.

The M10 and M11 specifically will "remember" the last manual code you entered, and keep on using that setting whenever any uncoded lens is mounted. This effectively gives you one (1) "free" 6-bit-coding, avoiding the need for menu-diving. I use that for my sole uncoded lens - a 1970s 50mm Summicron with too old a mount for Leica to update with 6-bit coding.

Edited July 25, 2023 by adan

[otto.f]

On 7/24/2023 at 6:05 AM, GFW2-SCUSA said:

I can't see I missed anything

I agree, sometimes I prefer the uncorrected version, for instance with B&W photo’s with my 75Lux or 35 Summicron iv. I get some vignetting then, and I like that. 

[BradS]

8 hours ago, adan said:

Frankly, I cannot remember what the "default behavior" for a brand-new M10 straight from the box is. Its menus may not yet be set for any particular lens. But as soon as you set one, the menu appears to select others, forever. In any event - the camera will take photos immediately. Push the shutter button, and the camera will not care what is mounted.

What does the code do? Automatically lets the camera's CPU know and record which lens is mounted, without any user effort required.

That does at least six things.
1) Let the camera know the focal length, which can be used to adjust the programming for the camera choosing Auto-ISO and shutter speed, according to the old formula for sharp hand-held photographs (shutter speed = 1/f - or 1/30th with a 28mm lens and 1/90th with a 90mm lens). With options to use 1/2x or 1/4x the focal length (i.e. 28mm > 1/60th or 1/125th instead of 1/30th)
2) Let the camera know the maximum aperture available.
3) Let the camera know the exact version and optical formula used, which can affect the following....
4) Let the camera know how much "digital" vignetting to expect, and correct for (a problem for compact M wide-angles lenses <50mm on digital sensors).
5) Let the camera know what "digital" color vignetting to correct for
6) Let the camera write the lens that was used for the image to the metadata/EXIF data, so that when editing you can see for yourself which lens you used, even 5-10 years from now. And in some cases apply corrections in post processing for distortion.

4) and 5) were Leica's primary reason for introducing the 6-bit coding in 2006 (with the M8). Digital sensors are simply different from film (flat textured silicon with limited ability to detact light from all angles vs. a thick gelatin coating that can be exposed from all angles).

Not everyone or every lens will need all of this data all the time - but it comes as a package when the lens is coded.

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!

 

With lenses 50mm and longer, the coding is less critical for clean color and other vignetting removal, but still has its functions.

What happens if you use an uncoded lens?

Again, not a lot if the lens is longer than 50mm - except that the camera will not necessarily correctly choosing an exposure time and Auto-ISO to reduce apparent camera shake. Or record accurate lens data to go with the picture.

Wider lenses will start to show the vignetting/color issues in the picture corners as they get wider. Some superwide M lenses are not compatable with or supported by Leica for color digital at all (although that improves slowly with each new digital Leica camera model). The very compact 21mm Super-Angulons from the 1960s; the Zeiss Hologon 15mm; and the Voigtlander 15mm lenses v. 1 and 2. You will get color bands or fringes of pink or cyan on the sides of a horizontal picture with those lenses.

If you want the accurate EXIF data and the corrections, you can take the time to enter the lens used manually in the camera menu. with every lens change.

The M10 and M11 specifically will "remember" the last manual code you entered, and keep on using that setting whenever any uncoded lens is mounted. This effectively gives you one (1) "free" 6-bit-coding, avoiding the need for menu-diving. I use that for my sole uncoded lens - a 1970s 50mm Summicron with too old a mount for Leica to update with 6-bit coding.

Thanks for this clear, concise and thorough explanation!  Answers like this make this site valuable.

[mmanda]

So I bought a meta bones LTM adapter for my 9cm Elmar. I’ve coded the adapter and the camera has stopped giving me the lens not connected error (that happened with the old eBay adapter I had) but now I can’t get the camera to select Auto detect lens.  It keeps reading the last manual lens I entered. 
 

Am I missing something?

[Al Brown]

3 minutes ago, mmanda said:

So I bought a meta bones LTM adapter for my 9cm Elmar. I’ve coded the adapter and the camera has stopped giving me the lens not connected error (that happened with the old eBay adapter I had) but now I can’t get the camera to select Auto detect lens.  It keeps reading the last manual lens I entered. 
 

Am I missing something?

Your old ebay adapter had a cut underneath exposing the 6-bit sensor, hence the lens not connected error.
If you cannot select auto detect with the new one the camera does not recognize the coding and keeps defaulting to manual - there is no harmony between your coding and 6-bit reader on camera. Very often the reader is super picky.

[AndreasG]

You need an adapter as shown right in the photo, otherwise the sensor window remains uncovered and gives wrong or no results.

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[KFo]

I use several LTM and of course uncoded lenses.  During my learning curve I discovered the issues with the style of adapters shown in this post.  The adapter the long notch around the circumference exposes, sometimes partially, sometimes completely the lens code detect sensor yielding the results describe above (no lens mounted) warning.

I have used gaffers tape to cover the sensor after the lens is mounted.  It allows "normal" operation.  

Run what you brung!🤠

1 hour ago, AndreasG said:

You need an adapter as shown right in the photo, otherwise the sensor window remains uncovered and gives wrong or no results.

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[mmanda]

Heres my coding attempt  - it looks rough on the enalarged image which my eyesight failed to show when I did it!   Do i need to clean it up more?

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And here it is mounted, the 6 bit reader is totally covered...  is it the adapter thats the issue?  

 

[RexGig0]

One thing to keep in mind, if one has more than one uncoded lens: IT IS NECESSARY to de-select and/or reset to the desired code, as one switches between/among one’s uncoded lenses.

Failure to de-select or reset could cause something like vignetting control for a wide-angle lens to be “baked-into” the file when one is using a longer focal length lens that vignettes less. Or, the camera may try to correct for a color shift that is not there. EXIF data will be erroneous.

Occasionally, I have forgotten to de-select or reset the lens code. To be more precise, I have forgotten on far too many occasions. Several of my uncoded wide-angle lenses perform well enough when coded as an Elmarit-M 21mm, 11134, anyway, so, it has not always been a problem.

Some lenses seem to do best when shot without any code entered. An example seems to be my newly-acquired Cosina Voigtlander APO Lanthar 50mm Aspherical.

Edited October 25, 2023 by RexGig0