Frameline masking/hacking for film M-bodies

[Greenhilltony]

Advertisement (gone after registration)

As far as I know, on film M-bodies, it is fairly easy to mask out the unwanted framelines, for example, the 75mm from 50/75, 135mm from 35/135. The secret lies in the brightline mask to be used, right? And I heard cameraworks-uk even made the metallic brightline mask to solve the issues on M3/M2 bodies. 

So while I’m thinking getting my M4 repainted black and mask out the unwanted 135mm framelines, I have a question: is it feasible to make a brightline mask to offer 35mm, 40mm, and 28mm (or leave 90mm alone) to satisfy the many users of Summicron-C 40/ Minolta M-Rokkor 40/ Voigtlander Nokton 40 and other rare 40mm lens to use them on Leica M-bodies, other than limited to the Leica CL, Minolta CLE or a certain model of Bessa? 

As far as I know, I came across a Leica M2 repainted and modified by Kanto to offer 28/35/50mm framelines (which is totally reasonable as the 28mm and 90mm M-mount lens share the same flange to activate the frameline selection mechanics).

[a.noctilux]

For 40mm framelines, I never see in M but why not, everything is possible (try asking in China).

Masking the 135 framelines should be easy.

As 35mm user myself, I see the 135 brackets as guide for composing.

I have ( VF exchange from previous owner ) M2 with M4 framelines mask and happy having those 135 brackets.

[adan]

16 hours ago, Greenhilltony said:

I have a question: is it feasible to make a brightline mask to offer 35mm, 40mm, and 28mm (or leave 90mm alone)

Just bear in mind that:

1) there are actually TWO overlapping frameline masks or stencils in the M viewfinder.

One with all 6 lines with the correct spacing/framing, as you usually see them.

And ANOTHER with all six slits OFFSET one way or the other, which slides diagonally to cover or reveal only parts of the first mask.

As lenses are changed, or the selection lever is moved, this reveals only two of the six "rectangles" at any one time, in the classic pairs: 90/28, 50/75, 35/135.

You would need to produce "40mm" versions of BOTH the main stencil AND the masking stencil, with the correct offset from each other - and then reassemble them correctly, also with very fine precision, with other precision parts (levers, hairsprings, etc.)

2) the mask material is very thin sheet-metal with slits cut to form the lines, that needs to slide easily, one mask past the other, once assembled. One crinkle in that thin metal, and one has to start all over with fresh parts.

Look at the final snapshot ("Components [sic] parts of M6 rangefinder mask") on this web page:

https://www.angelfire.com/biz/Leica/page10.html

...to see the disassembled frameline mechanism, and the actual masks (FRAME 1 and FRAME 2) just about life-size:

Edited January 26, 2024 by adan

[Greenhilltony]

2 hours ago, adan said:

Just bear in mind that:

1) there are actually TWO overlapping frameline masks or stencils in the M viewfinder.

One with all 6 lines with the correct spacing/framing, as you usually see them.

And ANOTHER with all six slits OFFSET one way or the other, which slides diagonally to cover or reveal only parts of the first mask.

As lenses are changed, or the selection lever is moved, this reveals only two of the six "rectangles" at any one time, in the classic pairs: 90/28, 50/75, 35/135.

You would need to produce "40mm" versions of BOTH the main stencil AND the masking stencil, with the correct offset from each other - and then reassemble them correctly, also with very fine precision, with other precision parts (levers, hairsprings, etc.)

2) the mask material is very thin sheet-metal with slits cut to form the lines, that needs to slide easily, one mask past the other, once assembled. One crinkle in that thin metal, and one has to start all over with fresh parts.

Look at the final snapshot ("Components [sic] parts of M6 rangefinder mask") on this web page:

https://www.angelfire.com/biz/Leica/page10.html

...to see the disassembled frameline mechanism, and the actual masks (FRAME 1 and FRAME 2) just about life-size:

Thanks for the information, learned a lot about the rangefinder mechanisms and history. It seems blocking lines is in deed much easier than making new lines. It’s a surprise to me that the fascinating yellow tint of the framelines and rangefinder patch in M3 and M2 is in fact a sign of oxidized balsam. 

[hansvons]

20 hours ago, a.noctilux said:

As 35mm user myself, I see the 135 brackets as guide for composing.

That is exactly why I would not mask them.

[250swb]

Frameline ‘problems’ (aside from can people see the 28mm frameline) are often down to being new to the camera. Everything can seem wrong when there is too much information especially if it isn’t needed. I hardly ever use a 135mm lens but I can’t think of the last time I found the 135 frameline intrusive because you learn to look past it, just as I hope people look past the car freshener dangling in their eyeline from the rear view mirror, or can see the TV even though their feet on the table take up their view.

[adan]

Advertisement (gone after registration)

There is a, perhaps apocryphal, story that at photokina 1954, when Leitz/Leica introduced the M system and its auto-selecting multiple-framing viewfinder, the head of Zeiss/Contax walked up to Ernst Leitz II, shook his hand, and said "You win!"

A few year later Zeiss dropped out of the interchangeable-lens rangefinder market. Matching the M viewfinder assembly was just too complex and critical a task.

At least until the turn of the millennium, newer manufacturing technologies, and the expiration of the Leitz patents.

When Konica, Hasselblad and Zeiss+Cosina all made creditable attempts to duplicate it (Konica Hexar RF, Hassy Xpan, Zeiss-Ikon) - but still couldn't sustain doing so, economically.

Edited January 26, 2024 by adan

[Stevejack]

On 1/27/2024 at 2:50 AM, 250swb said:

Frameline ‘problems’ (aside from can people see the 28mm frameline) are often down to being new to the camera. Everything can seem wrong when there is too much information especially if it isn’t needed. I hardly ever use a 135mm lens but I can’t think of the last time I found the 135 frameline intrusive because you learn to look past it, just as I hope people look past the car freshener dangling in their eyeline from the rear view mirror, or can see the TV even though their feet on the table take up their view.

I don't mind the 35/135 as much, I think due to the distance between the inner and outer framelines. The 50/75 I do find very distracting - they are too close together. I would love to mask out the 75 for a clean 50mm experience.

I like the external 5cm finder for this reason, but I must have deep-set eyes or something because on the external finder the framelines are a little too close to the edges for comfort. The OVF in the M3 is just perfect and it's a bit of a disappointment putting on a 50mm lens if I'm using an MP or digital M.