Proof of concept regarding self coding of lenses

[vikasmg]

Originally Posted by sean_reid

I doubt it. I would argue that it's in Leica's best interests to have this camera work with various lenses without needing to have them sent in for coding. I won't repeat my argument against a "closed system" for the M8 because I've explained it in other threads but I think that neither Leica nor the customer is well served by a closed system.

Sean

I agree. I'm an architect and I've often felt that the reason AutoCAD dominates the CAD market is that early editions of AutoCAD software were so easy to pirate that every student had one on his PC. We actually use a competing (and arguably better) product - MicroStation in our office and every new emplyee comes in knowing AutoCAD and has to be retrained!

- Vikas

[carstenw]

I just had the idea to add Lenses to the table which benefit from coding, even if they aren't Leica lenses. If someone successfully codes a lens, could they let me know? To be done right, some testing should accompany the coding, perhaps for vignetting improvements, as well as cyan corner removal, possibly.

[mike prevette]

Stan,

I have indeed. I'm just about to place an order for a bunch of them. I lost my last one, and need to stock up on them. I can't recommend them enough. I'm hoping they will smooth out the M8 crap trigger pull as well.

_mike

[marknorton]

This is a great thread, I wonder if Leica had anticipated our collective ingenuity?!?! Especially interesting that the coding works with a screwhead in the way - Coded lenses come back from Leica with that screwhole missing. The pre-ASPH 35/2 and Nocti are the ones I've seen so far.

The ability to code our own lenses - especially if Sean can come up with a screwthread solution - takes the heat off Leica to provide direct access for non-Leica lenses. We have it already, with the help of one of these magic pens.

[vikasmg]

Originally Posted by carstenw

I have placed the entire list here:

Leica M8

......

Thank you for that. Your document along with Bob Blakeley's template are the basis of a very usable kit. Now to look for a marker that won't come off as easily as a sharpie pen!

- Vikas

[puigvert]

21 f2.8 0XX000 = 24
24 f2.8 0XX00X = 25
28 f2.0 0XX0X0 = 26
28 f2.8 0XX0XX = 27 ? OLD 28 <-- Elmarit-M 35mm f/2,8 ?
28 f2.8 0XXX00 = 28
35 f1.4 0XXX0X = 29
35 f2.0 0XXXX0 = 30
50 f1.0 0XXXXX = 31
50 f1.4 X00000 = 32
50 f2.0 X0000X = 33
50 f2.8 X000X0 = 34
75 f1.4 X000XX = 35
75 f2.0 X00X00 = 36
90 f2.0 X00X0X = 37
90 f2.8 X00XX0 = 38
90 f4.0 X00XXX = 39

TE 16/18/21 f4 0X0000 = 16
TE 28/35/50 f4 X0X0X0 = 42

Summicron-M 35mm f/2 (IV) 000XX0 = 6
Elmarit-M 135mm f/2,8 (I/II) 00X00X = 9

[cme4brain]

Where on the popflash website is the coding for the lenses?

[cme4brain]

Originally Posted by sean_reid

Bob,

Thanks for making the template, it's great. I must say that this is one of my favorite threads in a long time. Thanks for everyone who is helping to get this figured out.

Update: Thanks to your template, I just successfully coded a CV 35/2.5 Pancake II as a 35/2.0 Summicron. This is great. I'll add a discussion of this to the article.

Cheers,

Sean

Now this would make me buy an M8, if I can bypass the closed leica system and use my non-Leica lenses! Great idea!

[carstenw]

Originally Posted by cme4brain

Where on the popflash website is the coding for the lenses?

You can find the entire table on the webpage in my sig. The Popflash coding is in the form of a picture of the codes for each coded lens that they sell, in the lens ad itself.

[carstenw]

Originally Posted by puigvert

21 f2.8 0XX000 = 24
24 f2.8 0XX00X = 25
28 f2.0 0XX0X0 = 26
28 f2.8 0XX0XX = 27 ? OLD 28 <-- Elmarit-M 35mm f/2,8 ?
28 f2.8 0XXX00 = 28
35 f1.4 0XXX0X = 29
35 f2.0 0XXXX0 = 30
50 f1.0 0XXXXX = 31
50 f1.4 X00000 = 32
50 f2.0 X0000X = 33
50 f2.8 X000X0 = 34
75 f1.4 X000XX = 35
75 f2.0 X00X00 = 36
90 f2.0 X00X0X = 37
90 f2.8 X00XX0 = 38
90 f4.0 X00XXX = 39

TE 16/18/21 f4 0X0000 = 16
TE 28/35/50 f4 X0X0X0 = 42

Summicron-M 35mm f/2 (IV) 000XX0 = 6
Elmarit-M 135mm f/2,8 (I/II) 00X00X = 9

I have all these. We don't yet have a confirmation for the old 28mm, but the Elmarit-M 35mm in your list, what is that doing there? Check the table in my sig.

[lct]

There is no such lens as Elmarit 35/2.8 which is in your list as well, Casten, if i'm not wrong. FWIW

[cbretteville]

Carsten,
Could you add a "last updated" time stamp to the page?

- Carl

[marknorton]

Interesting what that code 27 will turn out to be. Maybe it was the recently discontinued 28mm pre-ASPH Elmarit which might still have been around when the lens codes were issued.

Carsten, the 75/2 has never been available in chrome, interesting how may have been at some point but there's only 5 of them left now.

It's a pity there are no gaps in the range which might have hinted at a 28 Summilux or 24 Summicron down the road...

[Jamie Roberts]

Originally Posted by vikasmg

Thank you for that. Your document along with Bob Blakeley's template are the basis of a very usable kit. Now to look for a marker that won't come off as easily as a sharpie pen!

- Vikas

Carsten, Bob--thanks for doing this!! A wonderful service to the community... now I have to go buy markers

[stevme]

Coding for Leica lenses (without sending them in) or coding non-Leica lenses seems like a great idea, BUT Leica definitely has a copyright/patent issue here that should protect their technology. It's easiest to see in a case where, for example, Zeiss started to code their lenses, in competition with Leica lenses. I believe M mounts from other manufacturers were only possible once Leica's patent on the mounts expired.

So self-code at your own risk. It seems akin to downloading music without paying for it. It's done, but it's not legal.

Steve

[vincent1]

Originally Posted by carstenw

Inverting the digits (sorry, I had my logic backwards), the 75 Lux fits right in, but could you confirm the 35/2? With Black=1 and clockwise.

My apologies I got my zeros and ones reversed.for the 28 2.8 elmarit serial no 3608xxx the code is WBBWBB or 011011=27 I do not know the lens code .Sorry for the confusion,
Vincent

[frank_filippone]

If you look at the results from the Tri-Elmar, you will determine theat the camera body has the ability to check the position of the VF preview lever and to use that in determining what lens is on the camera. This means there are 3 x 64 different and unique lens signatures that can be determined internally.

We are going to see some overlap in the apparent coding on the lenses. However, with the preview lever also determining the unique lens, the apparent duplication of certain combinations of dots can be understood....

[artur5]

It is all so utterly simple. It seems impossible that Leica didn't thought of that before ( I mean users painting their codes on lenses instead of sending it to Solms )
Anyway I see the little CV ultrawides ( Cv12 and CV15) are left out of the game for the time being, no codes for them. I wonder if the Trielmar 16-18-21 code would be a feasible solution at least fo the CV15..

[Peter41951]

Self-coding would have to be done at owner's risk which is one reason why I guess Leica would refrain from supplying a kit, particularly if said lens is still under warranty.

[Joseph S. Wisniewski]

Originally Posted by mike prevette

None of my screw mount to M adapters were a possibility for this as they have a cut away shape where the lens sensor is. i.e. there is no material on the mount to draw on.

Thanks so much for those of you who posted codes. I will do a complete test tomorow regarding the effective ness of all this.

No telling how long sharpie (magic marker) will hold up on a lens mount. Using an end mill and grinding an indent + using enamel paint is a much more permenant method. But also more hazordess.

It appears that the marks aren't actually on a contact point on the mount. It should be possible to have a slightly thicker solution, such as a decal that would cover things like that Zeiss screw.

Originally Posted by mike prevette

I do not think this is an excusse for Leica to get away without providing us with manual contorl over the vignetting corection. That should be manditory. and please head Sean's advice about writting Lieca and telling them.

this whole coding system is bunk anyway. Any correction system that doesn't take into account shooting aperture can cause more harm than good. Imagine shooting with a lens that the firmware corrects for 1 stop of vignetting, at f8 when the lens renders no noticable vignetting. The camera wil still automaticly correct for it, and to your RAW data none the less. Thats unacceptable.

The vignetting that the coding system corrects for is dependent on the angle of incidence with the sensor, and is constant with respect to aperture. It's like Cos4 falloff, but more severe. So, you compensate just for that, by using the exit pupil location (which you get from the code), and leave optical path width vignetting alone. There's no "overcompensation". But it does let you see what the optical path vignetting is like, after you've removed the Cos4 and sensor angle vignetting.

Same with the radial color shift from the IR blocking filters. It's constant with aperture, changing only with focal length (which you get from the code).