M10-P and f info in exif files problem

[Telemetric]

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Hello!

I think I have a problem with my M10-P. 
There is no correspondence between the f that I set in the lense and the one that appears in the EXIF data of the file. 
In example, in one pic I set f11 in the lense and, in the exif data in lightroom it says that was taken with f4!!!!!

In Leica Germany they say me that is normal but i doubt it…

Any suggestion?

Thanks a lot in advance. 

Edited June 15, 2022 by Telemetric
Better title

[idusidusi]

Indeed it is 'normal' - the reason I believe is that there is no electronic contact between the MF lenses and the camera. There are of course the lens markings on the back of the lens (if it has been 'coded') - all my lenses have been, which tell the camera which frame-line to use. Originally I found that a pain, but now I don't bother.

Edited June 15, 2022 by idusidusi
Added thought

[jdlaing]

How do you think the camera would know what aperture setting you used?

[Telemetric]

Well, if is normal, is normal. 
In my Sony A7R4 i have data transfer between my Loxia lenses (manual also) and the cam…. so I though Leica had too…

 

 

[Telemetric]

5 minutes ago, jdlaing said:

How do you think the camera would know what aperture setting you used?

I don’t think nothing. I just supossee based on my experience using my Loxia manual lenses with my Sony. 

[a.noctilux]

Good idea = bad idea sometimes.

 

Leica put many things in the EXIF,

bad idea though with F number as stated the number is calculated from 2 (or more) readings from two (or more) cells.

Calculation as (no link or electronic transfering of f number from lens) can be fooled  by many things.

 

If I recall, first firmware ( when M10 launched 2017) did not include this f number in EXIF added in later firmware (maybe customer asked ?).

So many threads asking this "malfunction", once in a while since M8 🙃.

 

this

 

Edited June 15, 2022 by a.noctilux

[M11 for me]

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Thats good to remember as you wrote: In the beginning of the M10 the aperture information in the Exifs was empty. It came only later. But as @Telemetric writes it makes little sense when a real f/11 shows as f/4 in the Exifs. That big gap might be the exception. But still a difference of 1 or 2 LVs makes the information rather useless. 

[adan]

3 hours ago, idusidusi said:

Indeed it is 'normal' - the reason I believe is that there is no electronic contact between the MF lenses and the camera. There are of course the lens markings on the back of the lens (if it has been 'coded') - all my lenses have been, which tell the camera which frame-line to use. Originally I found that a pain, but now I don't bother.

To expand a bit on this -

1) 6-bit coding does not "tell the camera which frameline to use." That is done via one of the lens flanges, which comes in three different lengths (35/135, 50/75, 90/28) and presses on the same mechanism used by the manual frameline selector, to change the framelines visible. All mechanical, for backwards-compatability with 68 years of M lenses.

The framelines, BTW, are physical slits in a metal stencil and mask, not electrical LEDs themselves. They are backlit by an LED since the M (typ 240) in 2012.

2) The digital M cameras "guess" at the aperture (ever since the M8 in 2006) by comparing the amount of light coming through the lens as changed by the aperture, with a measurement of the overall "scene brightness" as detected by a second sensor on the camera front. However, that secondary sensor has a fixed field of view, so how accurate the guess is depends on focal length used, and how much variety of light and dark there is in the original scene. Photograph a black door centered in a white wall, or a white door centered in a black wall, and the estimates of the aperture in use will vary.

And again, the system works equally well (or badly) for a 1956 50mm Summicron "rigid" as it does for a 2022 50mm APO-Summicron-M-ASPH. That is a core design and engineering principle of the M system - very little will ever be added to an M lens or camera (e.g. electronic lens contacts) that would put previous cameras or lenses, dating back 68 years, at a disadvantage. Leica will go out of their way to use "creative engineering" to accomplish that.

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Edited June 15, 2022 by adan

[jdlaing]

4 hours ago, Telemetric said:

I don’t think nothing. I just supossee based on my experience using my Loxia manual lenses with my Sony. 

Well you are not using Loxia and Sony now. There are no electric contacts in Leica M mount lenses to be able to tell the camera what the settings are.

[jdlaing]

6 hours ago, idusidusi said:

Indeed it is 'normal' - the reason I believe is that there is no electronic contact between the MF lenses and the camera. There are of course the lens markings on the back of the lens (if it has been 'coded') - all my lenses have been, which tell the camera which frame-line to use. Originally I found that a pain, but now I don't bother.

The frame lines are selected mechanically by the mount on the back of the lens. The six bit code only identifies the lens to the camera.