A bit stuck (literally) on how to proceed taking apart this Liesegang Lens

The problem with oil is if you get some on the inside surface of the lens, now you have even more of a reason to get it apart to clean it. But may not be able to. A bigger problem is the oil may get onto the edge of the glass, which is probably a cemented doublet. That oil or any solvent may cause the balsam cement to start separating, pretty much ruining the lens.

Alright more progress!

The lens came apart partially after some more aggressive penetrative oiling.

But not at the expected spot as seen below:

https://i.imgur.com/KwPSxXb.jpg

I still think you guys were correct in thinking it also comes apart by the aperture wheel. So I'll address that as I go. Otherwise, there are interesting little screws that should blend into the circular rings:

https://i.imgur.com/yH7sIqy.jpg

https://i.imgur.com/q4AZyvq.jpg

So, I'll see if maybe those are holding the two sections together. One of them appears to be the center point of the rotating aperture ring or at least lines up with that.

I also think the element that was accessible after seperating, may actually screw out and has a metal ring attached to it to allow this as seen in this image:

https://i.imgur.com/x4ff9iZ.jpg

It looks like that part is threaded around the glass but is slightly bent too. maybe some more penetrating oil is needed.

Updates to follow.

Quote:

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Originally Posted by goamules

The problem with oil is if you get some on the inside surface of the lens, now you have even more of a reason to get it apart to clean it. But may not be able to. A bigger problem is the oil may get onto the edge of the glass, which is probably a cemented doublet. That oil or any solvent may cause the balsam cement to start separating, pretty much ruining the lens.

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This does concern me but I'll be careful as I go.

This lens is nearer a "Globe" lens than a RR version and the fixed maximum aperture looks nearer F.20 than the usual F.14.
So perhaps a 100+ degrees WA!

Later, well check this out!

https://www.the-saleroom.com/en-gb/a...9-a50000e9286f

This is a little earlier version of your lens.
The auctioneers refer to Gasc & Charconnet various versions of the Globe,

Quote:

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Originally Posted by Steven Tribe

This lens is nearer a "Globe" lens than a RR version and the fixed maximum aperture looks nearer F.20 than the usual F.14.
So perhaps a 100+ degrees WA!

Later, well check this out!

https://www.the-saleroom.com/en-gb/a...9-a50000e9286f

This is a little earlier version of your lens.
The auctioneers refer to Gasc & Charconnet various versions of the Globe,

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Thanks for the info. I saw that link before in my search. Interesting the limited amount of information on these types of lenses but I guess low production means limited copies to compare.

I did figure out that those interior blended screws adjust the detente resistence for the aperture. So either it can be loose or have definitive stops at rest. Interesting construction. I still can't get that section apart though unfortunately.

The glass on the other half though was easily cleaned and shows no etching from the fungus which is nice. I guess no coating helps with that. Hoping for the same result if I can get the other half apart to clean the glass as well.