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EZ Homemade 6bit coding


ckthual

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Hi,

 

I know the subject has been discussed, but I'm not sure my technique has been used, so I'm posting it !

 

I got my M9 a few weeks ago, and use old non coded lenses. So I tried to figure an easy way to code the lenses. I used the layout found here :

BoPhoto.com: M8 coder - simple manual handcoding of M lenses

and printed it on adhesive paper using the codes found here :

Leica M Lens Codes

(to be accurate, I used the coreldraw vector based file and filled the blacks on Illustrator)

I then cut it with an X-acot, stuck it on my lens, only keeping the important part (code only)

It took me a 3 tries in order to match the code reader and sticker, but guess what ? I finally worked, the M9 recognizes my lens ! :-)

OK, the paper I used may not last long, I'll try with another paper, I had to add some marker on it as it was a bit damaged in the first adjustment process, but I thought I would share this tecnique with you ! :-)

 

Regards

 

Cedric

 

PS/ very happy with my new M9 by the way, first pictures on my flickr > http://www.thual.net

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Well done. But- in your images you can see the paper rubbing off already. So to make it  permanent you need to get out your Dremel tool and mill the black spots and fill with paint (take care to mask the sensitive areas of your lens first).

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The only thing I'm missing is why this solution for an M9? I may understand it for the M8, but since the menu lens selection is working like a charm, I can't really understand. Did you find youself leaving the "wrong" setting frequently when changing lens? I may understand then.:confused:

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Without wishing to rain on your parade, as our American chums might say, Leica go to considerable lengths to position the sensor precisely in relation to the lens flange, to no worse than +/- 0.005 mm. A piece of paper is typically 0.1mm thick, never mind the self-adhesive goo you are using to stick it to the back of the lens flange.

 

That extra thickness, even when compressed by the lens mount will mean both the infinity stop and focus alignment will be off.

 

Other than that, and the lack of durability, it's a great idea...

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Without wishing to rain on your parade, as our American chums might say, Leica go to considerable lengths to position the sensor precisely in relation to the lens flange, to no worse than +/- 0.005 mm. A piece of paper is typically 0.1mm thick, never mind the self-adhesive goo you are using to stick it to the back of the lens flange.

 

That extra thickness, even when compressed by the lens mount will mean both the infinity stop and focus alignment will be off.

 

Not only that, having the tape just at one point on the lens mount means that the axis of the lens will no longer be perpendicular to the sensor. It will be tilted upwards and to the right, and quick Scheimpflug calculations suggest that with a 50mm lens focused at infinity the sensor plane, the nodal plane of the lens and the object plane will intersect about 20m above and to the right of the camera.

 

This came up 18 months ago - with Dymo tape rather than paper - and the person advocating it refused to accept that it could make any difference in practice. Since his test involved using the camera hand-held indoors he was probably right.:rolleyes:

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Cedric,

 

Allright, you are the first one to use the file I uploaded (at least the first one I know about)

 

I would use that xacto knife to cut out the holes instead and sharpie the lens.

 

The only place the coding strips worked were on CV lenses with recessed grove, however even there they started to wear pretty quickly, which is why I ended that experiment suggesting to simply use a sharpie. :-)

 

The important point here, there is simply no reason to purchase my template, as it is fairly easy to print and cut from the file and you have demonstrated that it worked just fine.

 

 

.

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It´s really quite easy to hand-code lenses. With all respect to those who manufacture and sell templates, you really don´t need them. What you DO need is a list of lens codes.

 

Now, get a thin Sharpie pen and take the lens off your M9. Look at the sensor and localise the 6 small red dots that are the actual sensors. Mark their positions on the lens mount surface and continue the marks down the outside of the mount (see image). That´s all the template you´ll ever need.

811034994_uPpcE-XL.jpg

 

Now, for the lens you wish to code, find the corresponding bit pattern in the list linked to above. Mount the lens on the M9, making sure that it locks in the correct position. Transfer those markings from the camera mount that correspond to 1 in the code listed (1 is black; 0 is white or the chrome of the lens mount). Remove the lens again, and transfer the markings carefully to the flat surface of the lens´ mount.

 

Now, widen these markings with the Sharpie, symmetrically around the thin lines you just made. The total width should be a little more than half the distance between the sensors in the camera. Let dry and try the lens on the camera, set to auto lens detection. Press the "Info" button, and hopefully you´ll now see the correct designation for the lens: that´s it...

 

Or, rather not... In my experience, at least, these markings will wear off very quickly, after just a few lens changes. But you can make them permanent, provided you

 

1) aren´t too hamfisted with tools (and own a Dremel or similar machine),

2) can bear the thought of actually grinding a couple of marks on the lens´ mount (don´t do it if the lenses are new and valuable; they´ll not be really harmed, but it does retract from their market value).

 

I´ve done it with three lenses, all from the ´60es, and rather well worn. It worked perfectly on all of them. I´ll describe how in the next post.

Edited by elgenper
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OK, so let´s make permanent codes.

 

First, a Rigid Summicron 50/2 (coded as Version IV, V for simplicity). Code is 100001, meaning the two end sensors have to see black, but none of those in between. Mark the lens as in the previous post with a Sharpie and try it to see if it works as intended.

 

If it does, you´ll now have to grind away some material from the lens mount, exactly where these Sharpie marks are now. Don´t make it deep; 0.1 mm is quite sufficient. Be careful to get straight edges on these grooves, exactly where the Sharpie markings end. Don´t mar the mount flange or the outside of the lens, obviously, and see that none of the dust gets into the lens (use masking tape if you want to be careful).

 

Now, fill the grooves with mat black enamel paint from a model shop, using a narrow brush. Don´t stroke the paint on; dab it down so it fills the groove completely without overflowing. Let it dry for some hours; now the paint has shrunk a little so it is safely below the surface of the mount, and so protected from wear. This is how my Summicron 50 looks now:

811035039_mrCzu-XL.jpg

(apologies for the bad images; I was in a hurry...

 

Try it on the camera; if you were careful, and the Sharpie marking worked, this one should, too.

 

Here´s my Summicron 35/2 V1 (coded as V 4), code 000110. Here, two adjacent sensors should read black; in such a case, you don´t have to make two strips; a single, broad one will work, and be easier to make. Here it is:

811035014_XZMng-XL.jpg

 

Finally, my old, "thin" Tele-Elmarit 90/2.8. This one gets the code 000100, with a single black mark. Also, it is by far the easiest one, since you don´t need to machine it at all; there´s a conveniently placed screw on the mount that lets the paint get below the mount surface (someone on this forum wrote about this; I think it was Any Piper, but I can´t find the post now). Allyou need to do is paint half the screw with white paint, and the other half with black. Here:

811035072_CH8Cb-XL.jpg

 

That´s it. Now, all my old lenses are coded.

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Guest ww@lt

I would propose a new option for the next firmware update:

 

1) the camera should allow you to mark all lenses, which you have, in the list.

2) if lens dedection is set to "automatic" and a uncoded lens is mounted, the camera only displays a short list of those of your lenses, which fit to the view-finder frame selected by the lens mount. (if only one fits, it can be set automatically)

 

this should allow a very quick selection in case of uncoded lenses.

(similar to the menu which is displayed on the M8, if a WATE is mounted)

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By the way, after my first several marks using Match templates (which worked every time) were wiped away onto the sensor, I took all my lens plates and sent them off to John Milich, who in two weeks engraved the recesses into the mounting plates-$35 US a plate. A little black and white nail polish, and it was permanently done, and I have not had an issue with recognition since.

 

The only lens I have not done is the 135 f4- does not have a code.

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  • 8 years later...

Hello,

 

Lucky me to find this newly revived old thread, now that I'm entering the world of Leica photography with an M8, the only affordable Leica camera for me. 

 

I bought a used M8 with only 1751 clicks on the shutter, and a Zeiss Biogon T* 2/35 ZM. Now I would like to code this lens so that I can refine my understanding of this camera by looking at the metadata (shutter speed vs aperture) on my computer.

 

The problem is that no matter how I code the lens (Summicron-M 35mm f/2 (IV) or ASPH) my M8 will not detect any lens info. Firmware version: 2.024

 

Has anyone else had this problem? Could it be that the sensor is faulty?

 

Other than this minor thing I am thrilled with this wonderfull piece of engineering.

 

Thanks in advance for feedback :)

Kind regards,

Fabian

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The big problem with the template was always the pen you used to make the marks with. Some permanent markers worked, some didn't, some stayed on for a few weeks, some rubbed off almost immediately. Personally I never found a marker that was both dense enough to register the code nor tough enough not to rub off almost immediately, although if you only have one lens this is less of a problem. I got the Dremel out and ground my own rebates into the lens flanges and used black paint which worked back then with lenses on the M9 and those lenses still work today with the M10.

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