Need help with the first complex lens board I've ever seen

[reddesert]

I have an idea ... Look up information about the ICA / Zeiss Juwel.

http://forum.mflenses.com/ica-zeiss-...as-t51144.html
https://www.flickr.com/photos/vajra23/32824516158

I've never held one of these. Some of them mount the lens with a bayonet, and the lock knobs/pins have some resemblance. I think one can also see where the finder may have been cut away from the black lensboard. There is a manual on butkus.org, although it doesn't describe the locking mechanism in much detail. Maybe it's hard to move from disuse or from being pinched by the mounting to the gray lensboard.

[Steven Tribe]

Just to confirm what has been suggested!
The rough black lens board has been removed from a scrap ICA Juvel - complete with the "smart?" shutter bayonet mounting device. Voigtlander had a similar system on the bergheil camera. See the diagram below.

[SParis]

Reddesert and Mr Tribe,
I think you're right! The Flickr picture of the front of the camera does have a very similar pin at 10:30. And the article says that a 15cm Tessar was standard on this model.
Steven, I think you're correct that the lens and board were taken off a Juval and mounted on the 114mm board.

The bad news is that this was a kind of DIY project, and I may find that the threads on the back of the shutter are damaged. I can see dribbles of some kind of black lacquer or glue around the threads.

I think the four screws on the back board are the key. I'm going to try drilling or grinding them out and see what is released. The good news here is that as long as the rear element is screwed into the lens, grinding on the back of the board won't shoot filings into the shutter.

We'll see if that solves the problem. I was hoping that this was an exotic but standard installation that someone here would know about, but apparently that's not the case.

[Jim Noel]

I would put drop of Acetone on the rear of each of the visible screws or bolts. Then I would drill them out.
I agree with other posts that this is obviously a poor effort to mount a lens to a board for which it does not fit.
It definitely was originally a bayonet mount for a Zeiss Jewel, or possibly a Bergheil. Once the most rearward board is removed by whatever means I believe the solution to the rest of the problem will be evident.

[SParis]

Thanks to everyone.
I think now I at least have a way to proceed, and I'm satisfied that I'm not missing/overlooking a simple and obvious way to dismantle the thing.
I think the easiest first step is to hacksaw through the two pins on the front (depending on how tough the material is) and see if that allows the lens to turn and presumably, unscrew from the board.

If that doesn't work, I'll have to find someone with a drill press and drill out the screws. Doing it by hand is too scary, because going a millimeter too far puts the drill into the shutter.

The round board on the back is steel, a little over 2 millimeters thick, AND a perfect fit on the back of the big board, so prying it off isn't an option. No way to get under it.

For what it's worth, here are two pictures of the back, one in soft light and one in direct sunlight.

[Sanford]

I would think that the pins on the front would be threaded and would turn out if you went at them with a pair of pliers. It would be easier than using a hacksaw, that is if it works.

[SParis]

Success!
I hacksawed off one of the pins.
It turned out that while it looked like the levers were just stopped against the pins, they were actually fitted into slots cut in the pins, and that engagement was what was holding the lens down.
Cutting one of the pins allowed the lens to move just enough to disengage from the other pin, and the lens was freed!
The bad news is that there is no retaining ring at all.
The good news is that it's a Compur 1 shutter and needs the same 41.5mm retaining ring as a Copal 1. Pretty easy to find.

I'll post pictures of the inner workings tomorrow, just for closure.

Thanks again to everyone who offered suggestions.

[SParis]

Sanford,
I tried turning the pins with pliers. Didn't work.
They appear to be riveted or maybe brazed onto the back of the black board.
Old-timey quality construction. :-)

[SParis]

Picture of the back of the lens.
Note that the things that I was calling "levers" aren't levers at all. They're non-moveable tabs, screwed into the back of the shutter. (They're at about 2 and 8 o'clock in this backwards picture.)
The picture of the front of the board isn't very informative, but it shows the scar from the sawing in the lower right, and the remaining pin in the upper left.

This was clearly a factory installation (on the small black board), but I really don't understand what the complicated structure accomplished. All it does really is hold the lens to the black board, which a retaining ring would have done just as well. This just adds extra parts and extra operations to the mounting process.

So, German engineering?

[Steven Tribe]

These mass produced German folding cameras had no separate lens boards/front standards. access to retaining rings was through the back of the camera when the ground glass panel was pulled out. changing lenses was not easy. Voigtlander and others developed these locking/release systems to avoid this cumbersome procedure for the benefit of the more adventurous amateur photographers who wanted try out lenses with different focal lengths etc.