M240 - Thickness of 6-bit mounts

[RFH]

So, I purchased a used M240. I wanted to add 6-bit coding to save time when switching lenses. Ordered two mount adapters with code cutouts, but upon arrival I found that they are both 0.05 mm too thin. The original Leica mount measures 0.99-1.00 mm, the new ones are 0.94-0.95 mm. This, of course, does not bode well for accurate focussing.

I have now switched back to the original mount.

Has anyone found a supplier of reliable 6-bit mounts for the M240?

 

[jaapv]

No- but what is wrong with coding the original mount properly? Either find one of the third-party technicians that will do it for you, or if you are able to do some precision DIY, get out the Dremel and model paint.

 

[Huss]

You could try this kit:

http://www.ebay.com/itm/Leica-M-Len...tal-Cameras-/181046019078?hash=item2a272f0406

 

[Godfrey]

So, I purchased a used M240. I wanted to add 6-bit coding to save time when switching lenses. Ordered two mount adapters with code cutouts, but upon arrival I found that they are both 0.05 mm too thin. The original Leica mount measures 0.99-1.00 mm, the new ones are 0.94-0.95 mm. This, of course, does not bode well for accurate focussing.

I have now switched back to the original mount.

Has anyone found a supplier of reliable 6-bit mounts for the M240?

I use two lenses that are coded and three that are not with my M-P. I set up the User slots: three for the ones without codes, one set to Automatic for the ones with codes. I'll have the uncoded lenses coded eventually, then I can use the User slots for other things. But this works well enough for the moment. 🙂

G

 

[Dante_Stella]

Try the adapters with various lenses before you draw conclusions. The thickness of the adapter is far from the only variable. The collimation of the lens, the position of the focusing cam on the lens, the rangefinder alignment of the camera, and the actual register of the camera are all tolerances that can add up.

Adapters from Asia have been a hair thinner for a while, and some lenses like a 21/2.8 can be incredibly sensitive to adapter thickness. And sometimes the Leitz adapters are the ones that don't work.

For a 50mm lens, an adapter that is too thin is harmless because the rf cam and the lens cell move at the same rate. One that is too thick will not focus to infinity.

But for many screw mount lenses, the fact that different adapter thicknesses exist can help you effect minor focusing corrections without recollimating the actual lens.

Dante

 

[CameraQuest]

So, I purchased a used M240. I wanted to add 6-bit coding to save time when switching lenses. Ordered two mount adapters with code cutouts, but upon arrival I found that they are both 0.05 mm too thin. The original Leica mount measures 0.99-1.00 mm, the new ones are 0.94-0.95 mm. This, of course, does not bode well for accurate focussing.

I have now switched back to the original mount.

Has anyone found a supplier of reliable 6-bit mounts for the M240?

Are you talking about screw mount to M adapters

or replacing the lens mount with a new code-able lens mount with bar coding indents?

 

[Fraser]

I've changed all the mounts on my lenses myself never had any bother, whats wrong with trying them on the camera and if they work they work. to pay someone £50-100 to change a lens mount does not seem worth it unless you really mess it up somehow, its always reversible.
Just don't use cheap screwdrivers!

 

[RFH]

Are you talking about screw mount to M adapters

or replacing the lens mount with a new code-able lens mount with bar coding indents?

Not the LTM adapters, but the regular mount with no thread. It messed up the infinity foucs on my 50 Summicron v.4.

 

[icebear]

People spent 7k on a camera, most of the time 2k or more per lens and want to cheap out on proper SD cards, batteries or don't want to get lenses mount updated and matched to the camera body to max out the performance of the equipment😉.
OK, never mind ... carry on.

 

[Dante_Stella]

People spent 7k on a camera, most of the time 2k or more per lens and want to cheap out on proper SD cards, batteries or don't want to get lenses mount updated and matched to the camera body to max out the performance of the equipment😉.
OK, never mind ... carry on.

Agreed. The M240 is much too high performance a camera to fudge how your M lenses fit. If we're talking about the Chinese flanges. they still have tolerance issues that could stack up badly with your camera body and RF.

One of the reasons to buy the Leica parts (or code original Leica parts) is that QC is infinitely more good, and you will have less of a chance of getting a flier.

That said, a layer of scotch tape under the mount is .05mm.

Dante

 

[Fraser]

People spent 7k on a camera, most of the time 2k or more per lens and want to cheap out on proper SD cards, batteries or don't want to get lenses mount updated and matched to the camera body to max out the performance of the equipment😉.
OK, never mind ... carry on.

I only use lexar cards and leica batteries and who's talking about matching lenses to cameras. I spent a lot more on my Land Rover Defender yet do all the servicing and work on that.
Two well known camera repairers tried to fix my 35mm Summilux and couldn't but I managed and that was a lot more complicated than swapping a lens mount.
Anyway I've only got a cheap M9😉

 

[jaapv]

People spent 7k on a camera, most of the time 2k or more per lens and want to cheap out on proper SD cards, batteries or don't want to get lenses mount updated and matched to the camera body to max out the performance of the equipment😉.
OK, never mind ... carry on.

Matching lenses to camera bodies is Internet baloney. Both are adjusted to a common standard.

 

[icebear]

Matching lenses to camera bodies is Internet baloney. Both are adjusted to a common standard.

If you shoot a 2/90 and 1/50 wide open the RF of the camera must be calibrated, sensor position should be checked. After that the lenses should be matched to the body. At least this has been done with my M9 and my lenses which were off at close distance. After the service focus is spot on. If the lenses already focus perfectly with the body, then be happy without service.😉

 

[jaapv]

Nonsense. The only matching done may be tolerance matching. Otherwise your lenses would be off with any other body.
I've got four digital M bodies, three film ones and nineteen lenses, everything is spot-on on everything. How could that be if lenses were adjusted to individual bodies ? The answer is simple : everything is adjusted to the common standard.

 

[icebear]

Nonsense. The only matching done may be tolerance matching. Otherwise your lenses would be off with any other body.
I've got four digital M bodies, three film ones and nineteen lenses, everything is spot-on on everything. How could that be if lenses were adjusted to individual bodies ? The answer is simple : everything is adjusted to the common standard.

Is that anything different to what I described?
My M9 was checked, RF calibrated on the bench and the sensor position adjusted to specs, this is the common standard, isn't it?
If that's nonsense to you, OK🙄.

 

[jaapv]

After that the lenses should be matched to the body.

This. Maybe I read it differently than you meant.🙂
The lenses are never adjusted to the body, but to the common standard.

 

[Ronald M]

I have use many Jin Finance flanges. One was thin on one side, thick on the other. All seem to be 40/1000" thick. NOMINAL Leica ones 39/1000", but I did have one 40. 1/1000 gets you free front focus even with 21 mm lens.

emery paper on glass lets you grind it down to 39, rotate stoke, rotate, stroke. Around 8 passes = minus 1/1000.
Chrome still left.

Now they focus and read fine.

Without a micrometer, you have zero chance of using these.

 

[Fraser]

I have use many Jin Finance flanges. One was thin on one side, thick on the other. All seem to be 40/1000" thick. NOMINAL Leica ones 39/1000", but I did have one 40. 1/1000 gets you free front focus even with 21 mm lens.

emery paper on glass lets you grind it down to 39, rotate stoke, rotate, stroke. Around 8 passes = minus 1/1000.
Chrome still left.

Now they focus and read fine.

Without a micrometer, you have zero chance of using these.

I do have a micrometer but until reading this thread never thought of measuring lens mounts and have changed all my lenses and they all focus perfectly.
I think you give leica too much credit for manufacturing accuracy/quality😉

 

[Manuel Patino]

I don't have a micrometer, but I am curious about these things. Could a dial caliper do a good enough job? I think it can accurately measure 1/1000" difference between any two mounts. I could remove and check them against each other and see....

Also, I bought a 70-200 Leica R lens and using the Leica adapter, I notice that when I shoot images of the moon, the sharpest images result at an indicated 10 meters by the focus ring. That is a bit away from the infinity mark... Seems that the moon should be focused properly at the infinity mark. Am I missing something?