Hi gals & pals!
So some time ago I “looted” my late dad’s man-cave. He had a PhD in optical engineering and was a massive analog stuff nerd, so lots of fun stuff laying around, a lot of which I can’t quite understand as I’m not that good with technical stuff.
But the apple doesn’t fall that far from the tree as I love misusing old gear for experimental photo, video and sound.
In the last box I collected there were a lot of spare lens parts (I think mainly for both scientific experiments and astral photography, but I dunno for sure), including this rad monstrosity I can’t comprehend.
It has no other markings than the Zeiss logo and the angle ruler, so I don’t know what it is called. It sorta acts like a periscope, but double-ended at one end. The big opening can be tightened to be attached to something, and it can also pop up.
It does seem to need a lot of light in order to work, so my guess is it has to be directed at a source of light like a screen, a rear projection, or a microscope.
In some ways it ressembles an Orytec TL-1001 8mm TV conversion lens I use for experimental photo and video (at least it works in similar ways)
It doesn’t have any diaphragm I can control, or focusing capabilities. No lens mount either.
If anyone has an idea of what this is, what its intended use is, I’d love to hear about it.
Could this be some sort of periscope thingy from a military vehicle or something? Or the fact that the other end is mirrored that it supposed to be underwater?
All those questions we wish we’d asked our dads when we had the chance.
It looks to me more of a scientific instrument than military.
The silver hinge suggests something that would be swung into place to make an adjustment, then swung out of the way to let the llight beam continue to another instrument.
The split image suggests some sort of alignment or focussing adjustment.
All guesses; the Edmund Optics catalogue has lots of vaguely similar gadgets - fun to look at but I couldn’t find this one.
If we saw pictures of the other parts from the same box, perhaps somebody might make a better guess.
So I asked my equally nerdy sister if she had any idea, and being a bit younger than me she suggested what I didn’t think of: ask an AI, like some advanced reverse image search.
It turns out this is called a Zeichenmicroskop. I didn’t find any full manual so I’m still not sure how exactly it works, but based on this picture of the manual I found it allows you to use a microscop and at the same time look through onto a piece of paper, thus allowing you to draw an exact copy of what is under the microscope.
The reason for having to make a drawing by hand rather than just fitting a camera and photographing the specimen is the very shallow depth of field at high image magnifications.
If you are looking at a biological specimen, only the very edges of the body or the legs or the eyebrows would be in focus at any focus setting. Typically the rest of the animal would be almost transparent. As you adjust focus, another part becomes visible and you see right through what you could see previously. Although you can sweep the focus through the specimen to build up a 3D model in your mind, any single photograph would make no sense at all.
It wasn’t until the 1990s that we started to put TV cameras on microscopes and use computers with depth-of-field reconstruction software that completely focussed microscope images of thicker specimens were possible.
Your gadget works similarly to a camera lucida, an optical device used by artists in the 1800s and more recently by David Hockney.
Thank you so much for the clarifications! I was wondering why there wasn’t any way to put a camera on the eyepiece, like a screw thing to put an adapter. Felt like it could have been an option even if this was from the 50s-60s.
I tried to put some lenses in it and yeah focusing is an issue
If it helps: your device is probably intended to fit on a microscope with a 160mm “tube length”, and microscope eyepieces of the time would be designed for a near point of perhaps 25cm - because the microscope operator is expected to make drawings, with or without this gadget.
Perhaps large-format camera lens or a projector lens might work in place of the microscope?
