Zoom?

[pjd]

I googled a bit, but I can't find any real world photos of that barrel. Like I mentioned, I don't need a zoom lens, and I doubt I would even want one, but it is interesting to think about.

Try searching for a "Zeiss Tele Tubus". I've got one, used it with a 9x12 camera. The tube needs a tele-negativ cell in the back plus your lens of choice in the front, often a Tessar or Protar. Some tubes have a focussing helical, others not. All the information to figure it out is in one page of some of the 30s Zeiss catalogues. The 45cm Magnar was another oddity from that era.

[Dan Fromm]

The catalog states: "The telephotographic lens consists of a collective element of long focus and a dispersive element of short focus, the combined focus being considerably lo nger than that of t he collective element, and is great er or less according to the separation of the two elements. This variability of focus enables one to obtain from a fixed standpoint pictures of varying size of one and the same object."

This sounds like a zoom lens to me.

No. The Rodenstock lens in the catalog page the OP showed and early Dallmeyer Adon teles aren't parfocal. Zoom lenses are, as the OP stated, varifocal and parfocal. Varifocal, variable focal length. Parfocal, plane of best focus doesn't move when the focal length is changed.

[abruzzi]

Try searching for a "Zeiss Tele Tubus". I've got one, used it with a 9x12 camera. The tube needs a tele-negativ cell in the back plus your lens of choice in the front, often a Tessar or Protar. Some tubes have a focussing helical, others not. All the information to figure it out is in one page of some of the 30s Zeiss catalogues. The 45cm Magnar was another oddity from that era.

Funny, a couple days ago I stumbled across the Tele Tubus in a 1901 Zeiss catalog. I found one for sale for pretty cheap, so I bought it just to see and play around with. I doubt it will even fit on my camera, and it doesn’t have a shutter. The one I found is a IV with a 25cm tessar on the front and a 10cm negative on the back.

[Bernice Loui]

Previously discussed on LFF:
https://www.largeformatphotography.i...-question-HELP

Interested in tinkering with optics-lenses in barrel without shutter, get a Sinar or Sinar_ish camera with a Sinar shutter (highly preferred as the Sinar system has the very least camera limitations of any view camera system that was produced) or Packard shutter, Drop guillotine shutter, rolling curtain shutter and this list goes on... Even just the lens cap works if the film exposure time is long enough.


Bernice

Funny, a couple days ago I stumbled across the Tele Tubus in a 1901 Zeiss catalog. I found one for sale for pretty cheap, so I bought it just to see and play around with. I doubt it will even fit on my camera, and it doesn’t have a shutter. The one I found is a IV with a 25cm tessar on the front and a 10cm negative on the back.

[abruzzi]

Previously discussed on LFF:
https://www.largeformatphotography.i...-question-HELP

Interested in tinkering with optics-lenses in barrel without shutter, get a Sinar or Sinar_ish camera with a Sinar shutter (highly preferred as the Sinar system has the very least camera limitations of any view camera system that was produced) or Packard shutter, Drop guillotine shutter, rolling curtain shutter and this list goes on... Even just the lens cap works if the film exposure time is long enough.

yeah the sinar shutter isn't something I know much about, but I'm aware of it existence. I was also considering (if I want to try out the lens in the real world) getting a cheap Graphic with the FP shutter (I'm also not that familiar with them, so I don't know which specific models have the FP shutter.) Before any of that, I want to see the lens in my hand to see whther its worth going through that (if other parts are non-functional, it might just become a shelf queen.)