Proof of concept regarding self coding of lenses

[marknorton]

Originally Posted by chetccox

Decimal equivalent from binary codes-

added 90mm f4 from previous post

21 f2.8 0XX000 = 24
24 f2.8 0XX00X = 25
28 f2.0 0XX0X0 = 26
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 f2.0 X00X00 = 36
90 f2.0 X00XX0 = 38
90 f4.0 X00XXX = 39

Interesting? I would guess the 75 lux to be X000XX =35

Not sure about the 90 f2.0 - the 90 f2.8 has a code of X00XX0 (38). You can also code the macro adapter, which I assume will be the same as the 90/4. I'm thinking parhaps the 90/2 is 37, the 75mm Summilux is 35 and the old 28mm f2.8 is 27. Using this scheme, original TE is 42.

[marknorton]

Original Pre-ASPH 35/2 has a code of 6...

[scott kirkpatrick]

Originally Posted by marknorton

Not sure about the 90 f2.0 - the 90 f2.8 has a code of X00XX0 (38). You can also code the macro adapter, which I assume will be the same as the 90/4. I'm thinking parhaps the 90/2 is 37, the 75mm Summilux is 35 and the old 28mm f2.8 is 27. Using this scheme, original TE is 42.

Here's where a Sharpie could take an M lens in a proper 28mm mount and mark it with the 27 pattern, to see what the camera tells us. Similarly, as I recall the 75 shows with the 50 frame, so see if you can mark a 50 to look like the 75/1.4 by giving it code number 35. Since 28 and 90 are paired (right?), wiping the 27 off the existing 28 and recoding it as a 37 will answer the final question in Mark's list.

scott

[brucek]

Originally Posted by marknorton

You can also code the macro adapter, which I assume will be the same as the 90/4.

The macro adapter has no code. Interesting...

Bruce

[chetccox]

Originally Posted by marknorton

Not sure about the 90 f2.0 - the 90 f2.8 has a code of X00XX0 (38). You can also code the macro adapter, which I assume will be the same as the 90/4. I'm thinking parhaps the 90/2 is 37, the 75mm Summilux is 35 and the old 28mm f2.8 is 27. Using this scheme, original TE is 42.

The entry for the 90 f2.0 was a typo. It should have been for the 2.8.
The others should fit in exactly as you mentioned.

[chetccox]

Corrected table

21 f2.8 0XX000 = 24
24 f2.8 0XX00X = 25
28 f2.0 0XX0X0 = 26
28 f2.8 0XX0XX = 27 ? OLD 28
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

left to right, code on top, black is X, white is 0

[vincent1]

Originally Posted by carstenw

Maybe you can use a purple one, Guy

I presume that the reading you did is counter-clockwise? Let's standardize on clockwise, it seems logical somehow. However, I would suggest that instead of 0 and X, where X means sharpie, we use binary. These are numbers. Standard in the computer industry is that 0 is black (like 'off'), 1 is white (like 'on'), and the easiest way to read the pattern is to place it at 12 O'Clock. Here are all the codes so far, read in this way (compared to previous chart 0 is 1 and X is 0).

16-18-21/4.0 Asph: 010101 = 21
21/2.8 Asph: 100111 = 39
24/2.8 Asph: 100110 = 38
28/2.0 Asph: 100101 = 37
28/2.8 Asph: 100011 = 35
28-35-50/4.0 Asph:
35/1.4 Asph: 100010 = 34
35/2.0 Asph: 100001 = 33
50/1.0: 100000 = 32
50/1.4 Asph: 011111 = 31
50/2.0: 011110 = 30
50/2.8: 011101 = 29
75/1.4:
75/2.0 Apo-Asph: 011011 = 27
90/2.0 Apo-Asph:
90/2.8: 011001 = 25
90/4.0:
135/3.4 Apo-Asph:

Still wanted: 28-35-50 T-E, 75 Lux, 90 Cron, 90 Macro, 135 Telyt.

my 35/2.8 pre asph 100100=36
my 75/1.4 011100=28

[vikasmg]

Originally Posted by hrosell

Street precaution – less attraction...
I've done plenty of shots in the street (architectural and parks) in rather questionable areas with two M6 and a R6.2 masked. You feel somehow safer this way...

Regards,

Horacio

Figures, I guess. Doesn't strike one so much out here in Singapore where street crime seems lower! Actually most people don't seem to know what a Leica is and how much it costs. Earlied this week though I was surprised when at a large dinner part someone I know sent me a text message enquiring about the cost of the camera!!

[Peter41951]

Is Leica going to code the 135/3.4 Apo-Asph?

[sean_reid]

Originally Posted by marknorton

Sean, with Mike's elegant coding solution, that kind of removes the need for user lens selection, doesn't it?

If we can get this to work reliably then yes it could be very useful. My Sharpie will be busy today when time allows. I don't yet see how this could work with the screw mount lenses because the adapters (at least the ones I have here) don't cover the 6-bit sensor. Maybe with a different adapter?

Cheers,

Sean

[sean_reid]

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.
_mike

I ran into that same problem last night. Darn...

Sean

[sean_reid]

Originally Posted by andybarton

Given that the vignetting and other characteristics of Zeiss lenses are likely to be completely different to those of Leica ones, the only advantage that I can see of this operation is to add the focal length to the EXIF data.

I can't see Leica objecting to that.

Hi Andy,

One of things that comes out in that 28s article is that the cyan cast is not so different and the vignetting of some lenses is also similar to that of their Leica competitors.

Cheers,

Sean

[Barmul]

To save a lot of time sending lenses back to Leica couldn't Leica provide a kit to carry out the coding by the owners of lenses? The kit would comprise of a template to lock into position on the lens flange and suitable markers to create the code. I do not think that this would be expensive and it would be another way for Leica to support their loyal customers.
My first posting in this forum. Best wishes to all.
Barmul.

[Jean LeBlanc]

Originally Posted by mike prevette

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.
_mike

My understanding is that this correction is for the difference between light rolloff caused by the digital sensor vs how the image is produced by film. So after the correction is applied, in theory you should be left with the same image you would have were you shooting film. At full aperture you'd have darker corners than you would at f:11, just as you would have with film. So if this is unacceptable, it would also have to be considered unacceptable when shooting KII on an M2.

[johnastovall]

This all looks like fun much on the level of making a pin hole camera with an Oatmeal box but if Leica wanted to do the right thing they would put this all in a firmware menu.

Why don't we rather than going out buying sharpies, take up collection and buy a Nikon D200 and send it to Solms. Maybe they could be inspired by the example.

[blakley]

In the meantime, here's a quick-and-dirty template. Print it out; the gray surround should be exactly 2 inches by 2 inches.Cut out all the white parts. The cutout at lower left aligns with the little recessed slot in the lensmount; the holes then represent the code bit positions. It's easiest to get on if you cut the recessed-slot piece all the way through to the edge of the paper so you can just open the template up and slip it on. I've made it a nice shade of magenta :-) If you want a template you can use over and over again, I'd suggest a trip down to Office Depot to get some overhead transparencies to print the template on. That way your sharpie won't damage the template.

[mike prevette]

Jean,

After rethinking the issue, I agree with you that it isn't eliminating all vignetting, it's only eliminating the vignetting it introduces. So my point is sort of mute. I still think we should be the ones in control of how much correction is applied to our raw data (beyond the typical data formating of course).

_mike

[robsteve]

Originally Posted by sean_reid

If we can get this to work reliably then yes it could be very useful. My Sharpie will be busy today when time allows. I don't yet see how this could work with the screw mount lenses because the adapters (at least the ones I have here) don't cover the 6-bit sensor. Maybe with a different adapter?

Cheers,

Sean

Sean:

I just looked at an original Leica adapter and it too had the cutout in the coding area.

I suppose you could screw the adapter on to the lens and then try the coding on the screw mount flange of the lens itself. You could even just put a piece of white tape on the lens and mark the coding on that. It is only a bit over a mm between the M flange and the exposed screw flange underneath. The coding may still work from that distance and if it does, it is less likely to wear off.

[sdai]

Originally Posted by mike prevette

I still think we should be the ones in control of how much correction is applied to our raw data (beyond the typical data formating of course).

Exactly my thought as well, Mike.

Also, no matter Leica does it with current 6-bit coding on the mount or, through adding firmware functions letting users input the lens data manually - such as Nikon is already doing with the F6, D2 and D200, ... I can hardly believe that Leica will include the optical characteristics mapping of other lenses from Zeiss, CV or whoever else - so as Andy says, all you get is the EXIF data ... who is in desperate need of that - certainly not me.

[jlm]

an interesting lens to hack would be the CV15, if a workaround for the missing metal can be found.

i looked at the new 16-21 tri-elmar at photokina: reading counter-clockwise at the lens base: w w w w B w. this would be a good shot fot the CV15