M9 lens coding revalation

[Robert_M]

Having done an extensive search and read all the info on lens coding, I set off to code the existing lenses I have for the M9. While experimenting with coding a VC 25P (f/4) as a elmar 24/3.8, I guess I was a little slopping in my makings and was able to bring up a different code while moving the lens mount around. The result was very interesting. This was purely accidental on my part....

- In the EXIF information, upon taking a pic, the lens code is 51-2 (ie 110011 and frame 24/35/135 position).

- The interesting part is that this brings up the M9 "info button" output identifying the lens as a "14mm/3.8".

So, it appears that the M9 firmware thinks the code 51-2 is a lens called 14mm f3.8. I'm using the latest firmware, BTW. Obvious questions to the forum readers:

1) Has anyone else seen this?

2) Is this a bug in the firmware?

3) Or, is this an indication that there is a 14mm f/3.8 lens in the development and they have put a place holder in the firmware.

Interesting?

RM

[ho_co]

Bravo, Robert!

Neat discovery that I haven't seen mentioned before. That would be a great lens, and if it's in the firmware, I'm sure it's on the way. Unless it's an Easter Egg. Maybe now that you've published the discovery, you'll be getting a call from Leica about becoming their chief programmer!

We'd all have to go out and buy another finder for it as well.

Now you are sure it said 14, right? Couldn't be 16 or 18 with a couple of your LCD pixels burned out?

Hot news!!!

[01af]

Originally Posted by Robert_M

This was purely accidental on my part ...

• In the EXIF information, upon taking a pic, the lens code is 51-2 (i. e. 110011 and frame 24/35/135 position).
• The interesting part is that this brings up the M9 "info button" output identifying the lens as a "14 mm f/3.8".

So, it appears that the M9 firmware thinks the code 51-2 is a lens called 14 mm f/3.8. I'm using the latest firmware, BTW. Obvious questions to the forum readers:

Has anyone else seen this?

No. You are the first person to report this (or anything like this), as far as I know. As a matter of fact; I already suspected that it might be possible to find out if the Leica M9 already knows about future lenses simply by trying out all the 6-bit lens codes so far officially unused (28 of them). However this must be carried out in conjunction with every possible 2-bit flange code (three of them). So if someone would want to check out all unused codes systematically, he had to try 3 × 28 = 84 combinations ... quite a lot a work.

Originally Posted by Robert_M

Is this a bug in the firmware?

No-one outside Leica Camera AG can know for sure ... but my bet is: No, it's not a bug. I think you're really on to something. Good find!

Originally Posted by Robert_M

Or, is this an indication that there is a 14 mm f/3.8 lens in the development and they have put a place holder in the firmware?

Yes, that is exactly what I'd think. Furthermore, I suspect there might be a few more placeholders like this hidden in the firmware.

Originally Posted by Robert_M

Interesting?

Interesting!? I'd say it's a sensation! A Super-Elmar-M 14 mm 1:3.8 Asph ... wow!

[Erik Gunst Lund]

Interesting find! I'll have to try this code for my Nikon 14/2.8 (Nikkor-F to Leica-M adapter) and test it on the M8 to see what happens.

[jaapv]

About 6500 Euro is my guess....

[k_g_wolf]

>> Jaap

Do they pay you for these ideas ?



Best
GEORG

[jaapv]

No I get free lenses... I wish....

[Viv]

Originally Posted by jaapv

About 6500 Euro is my guess....

Sounds about right.

The Zeiss 15mm f/2.8 costs 3,639 euro.

[Robert_M]

Yes, I'll verify that the camera indicates 14/3.8 and it is not mis-reading or broken lcd display (it is a month old camera). I was coding the VC lens as code 50-2 which is the 24/3.8 elmar lens and that shows up fine on the display. If one is a little sloppy on the last coding bit and turns the lens in the mount, then code 51-2 is activated. That is how I discovered this.

I'd suggest that someone else try this out and verify that it comes up on another camera. If someone has the 24mm/3.8 elmar lens they could temporarily blacken the last digit to test this out (ie, code 110011).
Since my M9 is new, it came with the latest firmware. I did not do an update. I don't know if this matters - it shouldn't.

BTW, one could try all the missing codes with just the 28 codes and a 35/135 mount. Then the entire 28 x 3 codes can be tested with the frame lever on the camera. This works for the 35/135 mount since it is the "relaxed" position on the mechanical activation. A 50/75 mount would only check the 50/75 and 28/90 codes with the frame lever and the 28/90 mount would only be able to check those codes. Hope that is clear.

[cbretteville]

51 is not a lens code that is in use currently, but it is interesting when you look at this find and that the Elmar 24/3.8 has been assigned code #50 and the Super-Elmar 18/3.8 #52.

You don't need to change the bayonets. The camera reads the lens id and preview lever setting as you press the shutter. You can simply move the lever to the other two positions using your finger before you trip the shutter and see if anything registers.

One thing Leica haven't done so far is to reuse a code for a physically coded lens (it is slightly different with the manually only settable ones). There is no reason why they couldn't, but so far they've stuck to the 63 different codes line so it is fair to assume that if you find a hit on one number, there is no need to test the other two positions of the preview lever.

Carl

[cbretteville]

A fellow LUF member emailed me and reminded me of the fact that the old and new 35/1.4ASPH shares the same code, which off cause they do. As far as these two lenses and coding/correction are concerned they are close enough to identical optically to be seen as one, floating element not withstanding.
Carl

[ho_co]

Originally Posted by jaapv

About 6500 Euro is my guess....

14mm finder goes without saying. Will there be a new version of the Universal Finder?

Will we be able to have the current Universal Finder upgraded for, say, 2000 Euro?

Will Robert Milich make an adapter to use the lens with UV/IR filter on M8?


Robert, have you been hired by Leica as Official Titillater?

[Robert_M]

No, I haven't been hired by Leica. But if you know where I can send a bill for my time spent in reverse engineering, I'd be happy to get paid....

cbretteville: One DOES need to cycle through all the frame positions if testing the missing codes. The Leica lens ID system uses redundancy logic to validate several codes. The frame position must match the code for that lens otherwise the coding is invalid (and identified as an uncoded lens). A prime example is the difficulty that people have had with coding the older Zeiss 25/2.8 lens since they came with 28mm frame mounts and Leica needs 35/24mm frame mounts for their 24mm codes. I understand Zeiss changed the 25mm lens mount to now have the "correct" frame code.

And, there ARE cases where all the frame lines are used for a lens. The 28-35-50 Tri-Elmar registers as 3 codes by using the 6-bit code and 3 frame codes. And, each of these 3 codes appears to have a different correction profile (in addition to the useful, correct EXIF info).

There are several manual input codes on the M9 which can not be activated by coding the lens itself. Those codes use the "0" frame line code (a non-existent state). This is rather frustrating in some cases. For example the wonderful 135/4 tele-elmar shares the 6-bit code with the 90/4 current lens. It obviously has a different frame line. But Leica decided to code the 135/4 as "0" for the frame rather than "2" (135/35 frames) so that only the manual coding input method will work correctly.

And, speaking of missing code numbers: I've wondered what 6-bit code "2" was saved for. I do not see it used on any of the lists. It is apparent that the single digit codes are legacy lenses and begin at the shortest focal lengths.

[deirdre]

I wonder what coding a Voigtlander 15mm as this lens would accomplish. It'd be less of a PITA than coding it as a WATE and having to select the focal length, that's for sure.

[exile]

Excellent idea Deirdre

[ho_co]

Originally Posted by deirdre

I wonder what coding a Voigtlander 15mm as this lens would accomplish....

And the CV 12! Wonderful idea! Bravo, Deirdre!

[Robert_M]

I do not know if there is an actual lens profile correction associated with this code in the firmware. Logic would suggest not since it requires an actual lens to make an appropriate code. I'll try to take some pics with this code tonight if I can. But I suspect this is just a place holder id in the firmware (or a coding bug....).

[01af]

Originally Posted by Robert_M

I do not know if there is an actual lens profile correction associated with this code in the firmware. Logic would suggest not since it requires an actual lens to make an appropriate code ...

I think a viable lens profile can be created beforehand based on a prototype lens ... or be computed right from the blueprints. So I'd expect an actual profile being associated with the 6-bit lens code 51 inside our M9 cameras right now. Having just an empty placeholder wouldn't make any sense. If you're going to need a firmware update to replace the placeholder with an actual profile then you can leave out the placeholder altogether just as well—or are you afraid someone else might claim that code point otherwise?

EDIT: But then, I could be wrong. I just tried fooling my camera into thinking the Elmar-M 24 mm Asph really was a 14 mm 1:3.8 lens (by sticking a little piece of black paper between lens and camera where the 6-bit code's least-significant bit is). It works! It really says, 14 mm f/3.8 on the Info screen. But after taking the shot, in playback mode the Info screen does not show any focal length (which for coded lenses it usually does). Also the vignetting at full aperture with automatic lens recognition on looks damn close to the 24 mm Elmar's when the lens recognition is off. I was expecting some over-correction ... so it seems I'm wrong and there is no profile stored for a future 14 mm lens. Oh well ...

[Robert_M]

O1af,
Thanks for verifying the coding and thanks for saving me the time to try out the profile. Although the info before exposure suggests a lens of 14mm/3.8, the EXIF info (try using exiftool on the file) lists the lens ID and lens type as "unknown (51-2)" and the focal length as 0mm. It appears to me that the following steps take place in the coding
1) The code is recognized and listed in the info before a pic is taken
2) The proper info is recorded in the exif when the picture is taken. This includes a text description of the lens used (this text seems to be the same for all programs that pull it up). At the same time, the focal length is recorded in the exif.
3) The exif recorded info is pulled up in the re-play of the pic on the screen just as it would be on an outside program.

My guess would be that any lens profile in the firmware is just a uniform weighted profile until something meaningful is available. At least, that is how most would program it. BTW, I'm still not convinced that someone just goofed in putting in code 51-2 in the firmware and wasn't supposed to be there. I still want someone to try code 2 if possible.....

[beewee]

Maybe you've discovered an easter egg in the firmware pointing to one of the "couple of nice things coming in 2011".