[Leica] Self-coding lenses, was Yellowstone

[pklein at 2alpha.net (Peter Klein)]

At 04:18 PM 9/24/2007 -0700, Steve Barbour wrote:
> > 35mm = 35/1.4 Summilux ASPH, B+W filter, hand-coded with a Sharpie.
>
>does this really work? how done... please?

Steve:  It does indeed work.  The Sharpie marks may wear off after a while, 
but you can always put them back on.  I will get my 35 'Lux coded 
eventually, but right now I'm going to hold off until the waiting times and 
reliability reports are better. This is a good stopgap.

See here:  http://www.digital-leica.com/lens_codes/index.html

That Web page has a list of codes, and also links describing the 
process.  Look also for the word "template" for a link where you can 
download a template you can print out.  Print it at "actual size," and cut 
it out. You can then use a razor blade, scalpel, etc. to cut out the little 
holes that match your particular lens.  Put it on the bottom of your lens, 
then use a fine-point black Sharpie marker to mark the lens mount through 
the appropriate holes.  Make the marks very dark by going over them a few 
times.  Only the black marks are necessary, the camera reads the silver of 
the mount as white.

Let the marks dry, mount the lens, set your menu to Lens coding "On" or "On 
plus UV/IR" as appropriate.  Take a picture.  Now view it on the LCD and 
press the Info button. If you see the correct lens focal length, you're 
done.  If not, use a Q-tip with a little acetone on it to erase the mark 
(wet it with one end and then dry it with the other.  Obviously, avoid 
marking or getting acetone on the glass or into the lens works.

Repeat until you get it right.  Took me two tries.  I had to extend my 
marks a bit beyond the template toward the outside of the lens before the 
camera read them properly.

Also see here:
<http://www.l-camera-forum.com/leica-forum/leica-m8-forum/10494-proof-concept-regarding-self-coding-lenses.html>
for the thread on L-Camera-User that started it all.  It contains all the 
discussion and various other methods for getting the codes in the right 
place.  If you have a steady hand and good spatial perception, you might 
not even need the template.  The "pioneer" used a piece of adhesive tape on 
the camera body to mark the position of the coding sensors, then marked the 
side of his lens mount, then transferred the marks to the bottom of the 
mount.

Disclaimers:  This is all unofficial, unapproved by Leica or the FDA, and 
is void where prohibited.  Don't blame me if you mess up your 
lens.  Batteries not included.  I'm not a doctor, nor do I play one on 
TV.  But you are.  :-)

Seriously, check the EXIF data on my Yellowstone photos.. Everywhere you 
see "35mm," it's those little black marks at work.

--Peter