Frameline mask lens separation on M5

[Oups c'est flou]

Hello everyone, I'm usually just a reader of this forum but I have had a problem for the past two years and I'm hoping someone could help me with it.
First, a picture of the culprit :



So, I bought a battered (but cheap !) M5 5 years ago and noticed that the RF patch had what looked like fungus on it, on the periphery only. It's also visible on the 50mm framelines and a bit on the 35 too. For a while it didn't bothered me too much as focus was still easy (and fully working) and it wasn't evolving. But then after a trip, bubbles appeared out of nowhere right in the middle of the RF patch!
I thought that the fungus had grown and somehow released gas in between the cemented elements.
Unable to find the exact location of the fungus and not keen to fork out 200€+ for a new RF assembly, I used it in this state. It's distracting, but focusing is still possible. even inside the "bubbles" the secondary image is strong and aligned.

I recently came across posts that talked about the aging optical cement rather than fungus as an explanation of this problem, and pinpointed it specifically to the frameline mask and its cemented negative element , present on all M until late m4-2. It's apparently this negative element that was removed from the RF on late M4-2, M4-P, M6 & M7 (and a flat mirror replaced with a concave one) and caused the infamous RF flare that was eventually resolved with the MP by putting this lens back in !

Camerawork is offering an upgrade to this frameline mask by the mean of a new "Free to air" mask, that apparently improve contrast and brightness of the RF patch for all M that have this cemented element.
I can't afford their service , but I have experience in camera repair (and I've already taken my m5 apart, i feel confident enough), but I don't have access to a laser cutter or any mean of making my own frameline mask (not even talking about the knowledge to design it !) but I was wondering if removing the negative element from my existing frameline mask would do it. and if so, what would be the impact on the RF?
Would my M5 become prone to finder flare ? (apparently the concave mirror, and not the absence of the negative element, is to blame for this. But you never know)
Would it work?

Maybe it's just easier to find a spare part, but where ? I was unable to find one at a reasonable price (I'd rather buy a Nikon F with plain prism than a spare part..for the price some seller are asking).
Also, even if the frameline mask is similar on the M2 and 4, I would prefer to find an M5 one. The framelines are a bit different and I'm pretty sure the bottom 35mm frameline on the m5 is just the meter readout bar.

Anyway If I can I'd like to try removing the negative element. So what are your thought on this? What's its purpose? it's around the RF patch but not directly on it (there seems to be a cutout in the lens in the middle. But I could be wrong) so I don't think it plays a role in the patch itself, maybe just the framelines.

I really love my M5 , it's my first and only M that I bought together with a CV Nokton 40/1.4 SC as a self present for my 20 years.. I cannot stand to have its RF flawed like that. It feels like I broke my arm but never got a cast !

also, don't pay too much attention to my English skills 😛

Thanks for reading me !

 

[MikeL]

Have you tried cleaning your frameline mask? I had some bubble-like stuff show up in my patch and I found a thorough cleaning of the mask (after removal) took care of it.

 

[Oups c'est flou]

Have you tried cleaning your frameline mask? I had some bubble-like stuff show up in my patch and I found a thorough cleaning of the mask (after removal) took care of it.

I tried cleaning the front facing part with a Q-tip and some alcohol, but it's just too small. I did not tried the other side though.
But I'm curious about how you cleaned it. How could these bubbles be accessible from the outside? Did it looked like my attached picture?

 

[Rob-F]

I'm suspecting that the "negative element" you mention might be the condenser lens that Leica omitted form the M6 and M7 for a while to save money. If so, the answer is yes, it will cause flare to remove it. I had DAG put the condenser back in my my M6.

 

[Huss]

Your rf patch is delaminating. Happened to my M5. It will fail and you will not be able to focus. I initially had Sherry Krauter repair mine, but then had to get DAG to fix what she had messed up (forgot to put in the condenser lens so it flared - it never flared before).
Sherry did not want to own up to her mistake which is why I went to DAG. He also masked off the 75mm frame line that Sherry put in which I did not want.

 

[Oups c'est flou]

I'm suspecting that the "negative element" you mention might be the condenser lens that Leica omitted form the M6 and M7 for a while to save money. If so, the answer is yes, it will cause flare to remove it. I had DAG put the condenser back in my my M6.

Yes I know, I did talked about it in the original message (though I don't blame you for not reading it, I tend to write in unpalatable blocks.). But I read in another post here (Can't find it!) that someone asked leica directly about what causes the flare and they answered that a concave mirror (flat in earlier cameras) was to blame. Even providing a precise angle at wich light will white out the path, about 110° if I recall. (In wich direction?)
Also, I didn't see any user report of the FTA mod from Camerawork talking about flare. So I'm hoping it won't happen on the account of the flat mirror in my M5.

Your rf patch is delaminating. Happened to my M5. It will fail and you will not be able to focus. I initially had Sherry Krauter repair mine, but then had to get DAG to fix what she had messed up (forgot to put in the condenser lens so it flared - it never flared before).
Sherry did not want to own up to her mistake which is why I went to DAG. He also masked off the 75mm frame line that Sherry put in which I did not want.

If you had 75mm framelines in your finder, she must have used a M4-P or M6 mask instead of an M5. That would explain the lack of condenser. it seems unlikely that she would have just forgot to put a lens in. Especially if this lens is supposed to be cemented.
Anyway I'm straying away from the subject.
I'm aware that it is separating and will eventually fail, sadly. But I'm wondering if I can boil the mask to remove the condenser and any trace of optical cement , and still get away without messing up my rangefinder.

Alternatively, recementing the condenser after boiling it? Is it feasible ?

[Edit] : Is the material used in the frameline mask resistant to heat? Is it a shet of glass or some kind of plastic? I don't want to deform it trying to decement it..

 

[MikeL]

Your rf patch is delaminating. Happened to my M5. It will fail and you will not be able to focus. I initially had Sherry Krauter repair mine, but then had to get DAG to fix what she had messed up (forgot to put in the condenser lens so it flared - it never flared before).
Sherry did not want to own up to her mistake which is why I went to DAG. He also masked off the 75mm frame line that Sherry put in which I did not want.

Huss, the frameline mask is delaminating? Or do you mean the prism is decementing?
I see fungus on the glass in his frameline mask, but hadn’t seen the lines/bubbles on a patch before. Just curious.

 

[mooge]

salut, polyarthus -

As far as I can guess (i.e. probably correct but maybe not) the frame line mask of the M3-M5 is made of two pieces - a piece of glass with the frame lines photo printed or something onto them, and a flat piece of glass with that concave element on it. The two are cemented together with Canada balsam and when the cementing starts to go you start to see lines and stuff in focus through the viewfinder, in the frame lines or RF patch.

I think you can fix this by removing the frame line mask from the RF/VF assembly; dissolving the Canada balsam in alcohol or something, and recementing the mask. You can see what the frame line mask should look like here - item #6 in figure #42 of this thread.


That said, I'm not super sure if this is all correct, but that's how I've been thinking about tackling a similar problem I have with my M4 and M2.

 

[Oups c'est flou]

I think you can fix this by removing the frame line mask from the RF/VF assembly; dissolving the Canada balsam in alcohol or something, and recementing the mask. You can see what the frame line mask should look like here - item #6 in figure #42 of this thread.

Salut, Mooge ! Thanks for replying,

I already knew about the thread you linked. Very informative thread by the way, not just for the frameline patch !

My plan (after I finish shooting the film currently in my M5 😛) sounds like yours, but I wonder if canada balsam can dissolve in alcohol? Or in anything, really? That's why I thought about boiling it, I've heard of decementig lenses like that. The potential problem here is that I don't know what material was used in the framelines mask. Alcohol probably doesn't pose a problem, but if alcohol doesn't cut it and I resort to heat, I hope nothing will wrinkle/shatter/melt .. Also if camerawork Uk resorted to laser-cutting a new mask, maybe they already tried this option and it failed? Or maybe I'm overthinking.

The more I think about it, the more I wonder about the usefulness of this negative lens if one can remove it entirely without compromising the RF integrity.

You have a similar problem with your M2 and M4 you say? Is it that common?

 

[Oups c'est flou]

Ok so after some research, it appears that canada balsam can be diluted in Xylene. I may try that instead of heat. Xylene seems easy to obtain, too.
I have an ultrasonic cleaner, maybe it will be enough to decement and clean everything.

But did Leica used Canada Balsam or another optical cement?

 

[Huss]

Huss, the frameline mask is delaminating? Or do you mean the prism is decementing?
I see fungus on the glass in his frameline mask, but hadn’t seen the lines/bubbles on a patch before. Just curious.

Prism is decementing/delaminating which causes the lines/bubbles on the patch. It will be usable until it lets go, then a black patch. Been there..

 

[mooge]

I'm pretty sure Leica used balsam until the M4-2 since from there onwards it seems like separation isn't a common issue. So, it's likely your M5 has optics cemented with balsam.

For sure, try xylene or some other solvent before going to boiling/heating. Ultrasonic might help (?) but try the easier stuff first before going to more aggressive methods. for what it's worth, I threw a shutter speed dial in my ultrasonic cleaner to try it out and it took the paint out of the numbers...

I'd leave that negative lens as it is. I'm pretty sure it's part of one of the glass plates so I don't think it's trivial to remove it.

I dunno if frameline separation is a common thing, but I only buy crappy Leicas (because I don't have money for nice things, but also I have 5 leicas now...??? jeeze) and crappy leicas means they have problems.



If you're keen on making your own frameline mask, why not look for a laser cutting shop? I dunno where you're at but there's one in my area .