How to add 6-bit codes to a lens?

[robgo2]

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I have several uncoded M-mount lenses that I use regularly on my SL. I have purchased replacement flanges that have cutouts in the area where the codes are located. I know where to find the appropriate codes for my lenses, and I have a black marker pen to do the job. My question has to do with the non-black portions of the code. Should they be painted white, or can they be left as bare metal?

 

Thanks,

Rob

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[thighslapper]

The coding sensor measures light ...... the problem is making the black bits black enough and in the right places .... and reflected light at all will make the sensor register 'white'. There is no need at all to bother with the white bits. 

 

In fact I've often thought it would be more sensible to paint the whole area black and just add a few white dots in the right area ...... the sensor is very sensitive. 

 

If it doesn't work or you get the wrong result it usually means the black areas aren't big enough. It may take a bit of trial and error. I laser printed a master layout plan with the flange holes marked on it on Overhead Transparency Film ** so I could align with the flange and check I had things in the right place, but there are plenty of other ways of doing it.  

 

There have been some issues with replacement flanges not being the right thickness (not an issue with the SL) or an uneven thickness resulting in part of the sensor image being OOF. Some have also been either sloppy fits when the lens is mounted .... or far too tight. You get what you pay for. If they work, fine, but I would check everything fairly thoroughly with some test shots before congratulating yourself on having saved some cash ..... 

 

** This prints out the right size on my printer on A4 paper or film......  leica 6 bit template 2013v3.pdf. I used to cut one of these out ...... cut out the centre and the 6 bit holes carefully with a small craft knife, slip it over the flange, align it then mark the spots that need to black then dremel them out and fill with matt black enamel. Always try the template with coded lens to make sure the register points and code marks are in the right place. Some flanges have different screw arrangements although the D shaped notch is constant.They are a tight fit and you need to cut out the centre aligned with the outside of the marked circle. 

[ramarren]

I have several uncoded M-mount lenses that I use regularly on my SL. I have purchased replacement flanges that have cutouts in the area where the codes are located. I know where to find the appropriate codes for my lenses, and I have a black marker pen to do the job. My question has to do with the non-black portions of the code. Should they be painted white, or can they be left as bare metal?

 

 

For most consistent operation, I would paint the cutouts with matte-finish enamel in the appropriate black and white code pattern. I found just marking the blacks produced inconsistent results. (Normally, I prefer to have my lenses coded by a professional. DAG has done two of mine, he machined the depressions and painted them.)

[thighslapper]

For most consistent operation, I would paint the cutouts with matte-finish enamel in the appropriate black and white code pattern. I found just marking the blacks produced inconsistent results. (Normally, I prefer to have my lenses coded by a professional. DAG has done two of mine, he machined the depressions and painted them.)

 

 I have never painted the white bits and never had any problems and I've self coded all my Zeiss + Voigt lenses as the nearest M equivalent and half a dozen M lenses. It's the black bits that cause all the trouble, particularly if you make then too narrow or get the alignment slightly off. For some lenses you only have to machine one or two pits and paint them black, making the job much easier. 

[scott kirkpatrick]

Black goth nail polish has worked for me.  I have left the white pits bare metal.

[ramarren]

 I have never painted the white bits and never had any problems and I've self coded all my Zeiss + Voigt lenses as the nearest M equivalent and half a dozen M lenses. It's the black bits that cause all the trouble, particularly if you make then too narrow or get the alignment slightly off. For some lenses you only have to machine one or two pits and paint them black, making the job much easier. 

 

 

I'm glad that's worked for you.

 

I was switching lenses between M9 and M-P bodies, then the SL body, and noted that the results were inconsistent until I painted all the digits properly. Then I had them coded professionally when I bought the M-D: no further issues at all. 

 

I don't use M lenses on the SL very much anyway. I prefer SL and R lenses on the SL.

[thighslapper]

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I'm glad that's worked for you.

 

I was switching lenses between M9 and M-P bodies, then the SL body, and noted that the results were inconsistent until I painted all the digits properly. Then I had them coded professionally when I bought the M-D: no further issues at all. 

 

I don't use M lenses on the SL very much anyway. I prefer SL and R lenses on the SL.

 

Having had an array of digital M's there is camera to camera variation on the sensors and alignment of the coded bits when the lens is attached. Some lenses can over-rotate and not align properly. None of it has much to do with the actual coding on the lens if it's done accurately. 

[ramarren]

I'm aware of this, TS. However, the fact remains that properly coding my lenses eliminated all the problems. I don't know why you're so dead set on trying to convince me that what I know worked didn't or wasn't necessary. It makes no sense. ?? 

[robgo2]

Well, I just received the replacement rear flanges, and they are thinner than the original flanges. Hence, no hard stop infinity focus. 

 

Back to the drawing board.

[pico]

In my modest experience, the best durable flat-black paint for brush application is Testors flat black RM11471_611, or depending upon your supply, RM11471 * where "RM11471" is the best indicator.

 

I've used it for decades. It is the answer.

[ramarren]

Well, I just received the replacement rear flanges, and they are thinner than the original flanges. Hence, no hard stop infinity focus. 

 

Back to the drawing board.

 

 

It's expensive, but having DAG or other repair professional do the work takes all the ambiguity out of it. It gets done right, and is warranteed. I'd call for a quote.

[thighslapper]

 However, the fact remains that properly coding my lenses eliminated all the problems. 

 

exactly 

 

I'll give anything a go and keep flogging away until I get it right ...... but there again I make jewellery as a pastime and have experience of clock and watch repairing, so this sort of thing is no big deal for me...... plus, as Leica just junk the old flange and just add a new suitably coded one it is a no-risk exercise.

[robgo2]

It's expensive, but having DAG or other repair professional do the work takes all the ambiguity out of it. It gets done right, and is warranteed. I'd call for a quote.

 

I just may do that.

[ModernMan]

Well, I just received the replacement rear flanges, and they are thinner than the original flanges. Hence, no hard stop infinity focus. 

 

Back to the drawing board.

 

 

May I ask, from where did you obtain the lens flanges? I've got some sketchy ones from eBay, which were not fabricated sufficiently accurately for use, IMHO.

 

On the other hand, the replacement flanges I've received from Leica (about US$150 each, pits machined, but unpainted), have been just fine. Generally I've found the thickness of original and replacement flanges to be within a couple of tenths (0.0001") at most. So, replacement flanges from Leica that are a different thickness than the original flanges on Leica lenses would to me be a surprise indeed.

 

Not a large sample, but I've only encountered lenses with flanges that were custom fitted with a non-standard thickness in a couple of situations on 1960's vintage or older lenses. Of course, its not clear if that was a factory original or a "repair". In one case (a goggled 135/2.8) the flange parallelism had been altered -- looked like a ham-fisted job LOL.

 

DAG is excellent (you'll notice he is afforded legendary reverence on this board, and for good reason), and he may even charge less to machine coding pits that Leica charge for a new flange.

[robgo2]

That's useful information, but the lenses that I want to encode are Zeiss and CV, so the flange thickness may be different than for Leica lenses. I wonder how much it would cost (with shipping and insurance) to send them to DAG.

[ramarren]

That's useful information, but the lenses that I want to encode are Zeiss and CV, so the flange thickness may be different than for Leica lenses. I wonder how much it would cost (with shipping and insurance) to send them to DAG.

 

 

Best thing to do is to call or email, and ask. Don is always busy, but he always answers emails promptly (unless I ramble on too much... ). 

dagcam@chorus.net :: (608) 835-3342

 

There are no alternative flanges available for the 1972 Summilux 35mm v2. He dismantled the lens, machined the divots into the flange, and painted them. Perfect job, and the lens was delivered back to me in two weeks end to end. 

[antigallican]

I bought ebay flanges, put them on and took them off. They were inaccurate.

[250swb]

Well, I just received the replacement rear flanges, and they are thinner than the original flanges. Hence, no hard stop infinity focus. 

 

Back to the drawing board.

 

Focus problems with replacement flanges (or even original flanges that have come loose and are causing focus problems) are caused by not centring the flange properly. The screws need to be tightened gradually opposite to opposite as much as possible until tight, otherwise despite the countersink holes it can be biased and cause stiff focusing. If it is simply that the lens no longer stops on the infinity mark I don't really see how this is a problem on an SL, infinity is still infinity, focus is done by looking at the EVF. The infill for the black should be as matt as possible, so markers and nail varnish is a bad idea as they can reflect light, so use either Tamiya Matt Black or the Humbrol equivalent.

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Hallo,

Look here: Leica L-Mount

[robgo2]

Yeah, but I like a hard stop at infinity. It makes focusing faster and less prone to small errors. It's nice to have, even if not essential.