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

[HoopsMcGee]

I picked this up at an auction today and I wanted to try to take apart this lens to clean it and try to fix the aperture which is stuck. Not much info is on-line with this lens in particular so I was hoping anyone may have any info and how to proceed.

The hood was removed with ease and the lens board ring that was attached as well. I think the base seperates even further and the brass part is another ring.

I also can't get into the front element.

If I can't do this myself, are there any know repair people that handle old lenses like this?

Thanks!

https://i.imgur.com/5k8wN4I.jpg

https://i.imgur.com/UtL42kc.jpg

https://i.imgur.com/L2tGiD5.jpg

https://i.imgur.com/57kXH7g.jpg

[HoopsMcGee]

Continued:

https://i.imgur.com/kbTadM9.jpg

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

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

[Steven Tribe]

Need lighter photos of the barrel and the exact engraving!
Liesegang never wholly commited themselves to mass production of taking lenses and eventually found their niche in projection lens design. But they seem to have kept an eye on their competitor's products and made small runs of similar lenses.

This could be something between the "Globe" lens and the wide angled RR/Aplanats. It looks a lot like the 1860's/1870's WA series from Gasc et Charconnet.

[HoopsMcGee]

Need lighter photos of the barrel and the exact engraving!
Liesegang never wholly commited themselves to mass production of taking lenses and eventually found their niche in projection lens design. But they seem to have kept an eye on their competitor's products and made small runs of similar lenses.

This could be something between the "Globe" lens and the wide angled RR/Aplanats. It looks a lot like the 1860's/1870's WA series from Gasc et Charconnet.

Thanks so much for the response!

What parts of the barrel for lighter photos? The entire inscription is shown in those images: “No. 12541 Ed. Liesegang Eberhold”

[goamules]

You are going to have to be an explorer to discover how to get this apart I fear. Everything that was assembled, can be disassembled. The trick it to do it non-destructively. The outside ends next to the glass don't look like the normal brass fittings that unscrew. There is no knurling. Therefore I deduce the glass was inserted from the INSIDE. So that means you may be able to unscrew the barrel, probably where that raised ridge is near the wheel stop. But nobody knows who hasn't taken one apart, and this is not a common lens, so I doubt anyone has in recent generations.

[HoopsMcGee]

You are going to have to be an explorer to discover how to get this apart I fear. Everything that was assembled, can be disassembled. The trick it to do it non-destructively. The outside ends next to the glass don't look like the normal brass fittings that unscrew. There is no knurling. Therefore I deduce the glass was inserted from the INSIDE. So that means you may be able to unscrew the barrel, probably where that raised ridge is near the wheel stop. But nobody knows who hasn't taken one apart, and this is not a common lens, so I doubt anyone has in recent generations.

Yeah I figured as much. The issue may be that the pieces are locked up as well. Would using a penetrating oil be outr of the question or too extreme in your opinion?

And yes there does appear to be a seam by ther raised area below the aperture wheel.

[HoopsMcGee]

Alright after messing around with it, I was able to get the back plate off But at this point it seems the hood and back plate are the only obvious removal bits. I definitely think you are right that the barrel assembly is the main point of entry. These lenses are fairly simplistic correct? Two elements only?

[HoopsMcGee]

I don't think it will be possible to do it by hand so any recommends for tools to safely grip the two halves and torque?

[HoopsMcGee]

Progress!

Tried some penetrating oil on the apparent seam in the middle of the barrel. Dabbed it with a toothpick and let it sit for about 5 minutes. Because of the proximity of the aperture wheel it also was unavoidable to get it in there too but figured it couldn't hurt too much and maybe it would oosen it up and lo-and-behold, the aperture wheel is now spinning. So, hoping for the best with the seam and will try to loosen the two halves in a bit with some more sitting. I have two thin strap wrenches but even though they are thin, both won't fit. I may have to try with rubber gloves on instead.

[HoopsMcGee]

Lol, the aperture ring froze up again. Back to drawing board. Needs some more aggresive oiling I think.

[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.

[HoopsMcGee]

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.

[HoopsMcGee]

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.


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

[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/auction-catalogues/auction-team-breker/catalogue-id-breker10004/lot-11efc14d-cfd7-4f36-88d9-a50000e9286f

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

[HoopsMcGee]

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/auction-catalogues/auction-team-breker/catalogue-id-breker10004/lot-11efc14d-cfd7-4f36-88d9-a50000e9286f

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

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.