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Jos-Pe Tricolor
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PostPosted: Tue May 16, 2023 2:29 pm    Post subject: Jos-Pe Tricolor Reply with quote
One of these showed up on eBay in my Steinheil feed. Weird looking camera but interesting.


https://www.ebay.com/itm/Camera-Jos-Pe-Tri-Color-Hamburg-Lens-Steinheil-Anastigmat-Quinar-2-5-10-5cm/354787249526?mkpid=0&emsid=e11021.m43.l3160&mkcid=7&ch=osgood&euid=24d262062c7b4b42945eca78a99f937a&bu=43938606560&ut=RU&exe=0&ext=0&osub=-1~1&crd=20230516064412&segname=11021&pageci=9aa2d790-3e8a-4eab-bacd-81965cd076f2&redirect=mobile


http://camera-wiki.org/wiki/Jos-Pe


PostPosted: Tue May 16, 2023 3:37 pm    Post subject: Reply with quote
Click here to see on Ebay without being tracked.


PostPosted: Tue May 16, 2023 3:48 pm    Post subject: Reply with quote
That is a 1926 Quinar. Like 1 small


PostPosted: Tue May 16, 2023 4:00 pm    Post subject: Reply with quote
Interesting camera body -- exposes 3 films at once through cmy filters(?) for combining into color image.


PostPosted: Tue May 16, 2023 5:32 pm    Post subject: Reply with quote
A good book on the subject of the early color photography and color printing developments is 'A half century of color' by Sipley. You will see some different designs of color separation cameras there. Some Ives designs, Bermpohl camera and more.


PostPosted: Tue May 16, 2023 6:14 pm    Post subject: Reply with quote
Thank you Ernst.

All smoke & mirrors lol

Quote:
These one-shot three-color cameras use internal arrangements of half-silvered mirrors to divide the light from the lens into three parts, and direct each part
http://camera-wiki.org/wiki/Three-color_camera

These are interesting too

https://en.m.wikipedia.org/wiki/Dichroic_prism

http://camera-wiki.org/wiki/Minolta_RD-175 -- "The camera has two green sensors, and one red/blue combination sensor, which is striped using microscopic filter elements."


PostPosted: Tue May 16, 2023 8:22 pm    Post subject: Reply with quote
its bad enough shooting with a single plate camera. It must have been a nightmare keeping up with which neg is which


PostPosted: Wed May 17, 2023 11:38 am    Post subject: Reply with quote
visualopsins wrote:
Thank you Ernst.

All smoke & mirrors lol

Quote:
These one-shot three-color cameras use internal arrangements of half-silvered mirrors to divide the light from the lens into three parts, and direct each part
http://camera-wiki.org/wiki/Three-color_camera

These are interesting too

https://en.m.wikipedia.org/wiki/Dichroic_prism

http://camera-wiki.org/wiki/Minolta_RD-175 -- "The camera has two green sensors, and one red/blue combination sensor, which is striped using microscopic filter elements."


I still recommend it. Way more information than I ever could write here and what your links show. You also experience how they struggled to get color photography and in general color reproduction working up to the 1950's.


Richly illustrated with reproductions of older color processes.


PostPosted: Wed May 17, 2023 3:19 pm    Post subject: Reply with quote
Ernst, I thank you for posting images of the interior diagram of the camera. Wondered how it worked. I had ideas but wasn't sure they were correct.


PostPosted: Thu May 18, 2023 12:54 pm    Post subject: Reply with quote
One of the major hurdles in the development of these three-plate color cameras was the development of films sensitive not only for blue light (original emulsions around 1850), but also for green (1884 => "orthochromatic") and red (1902, "oanchromatic"). Only plates sensitive to all colors could (by using corresponding filters) generate red / green / blue partial images which later could be processed and printed to get color prints.

Producing books with color plates must have been tremendously difficult before 1936. That's why I occasionally collect such books when I happen to see one in local book- abd thrift stores. Publishing books myself, I have a lot of respect for those "ancient" techniques, and the people who were able to get useful results under such difficult circumstances.

S


PostPosted: Thu May 18, 2023 6:49 pm    Post subject: Reply with quote
stevemark wrote:
One of the major hurdles in the development of these three-plate color cameras was the development of films sensitive not only for blue light (original emulsions around 1850), but also for green (1884 => "orthochromatic") and red (1902, "oanchromatic"). Only plates sensitive to all colors could (by using corresponding filters) generate red / green / blue partial images which later could be processed and printed to get color prints.

Producing books with color plates must have been tremendously difficult before 1936. That's why I occasionally collect such books when I happen to see one in local book- abd thrift stores. Publishing books myself, I have a lot of respect for those "ancient" techniques, and the people who were able to get useful results under such difficult circumstances.

S


Yes, the color sensitivity of B&W films was a major hurdle to overcome.

Halftone or continuous tone reproduction of photo's, a magical process in that period. Making screened halftone films after successive steps of masking (films, not layers) to compensate for color shifts that were bound to happen between not so perfect RGB filters and not so perfect CMY(K) dyes or pigments in the inks. Manual spot etching rotogravure cylinders as a last step retouch.
Collotype and heliogravure/rotogravure are my favorites when I buy secondhand books with B&W reproductions.


PostPosted: Wed May 24, 2023 10:27 pm    Post subject: Reply with quote
There's also a lot of light loss in the camera, so you either needed a stationary subject or fast film.
Three-strip Technicolor movie cameras used a similar dichroic mirror system. Super-X movie film was developed to make that feasible, as the shutter speed is fixed. Huge amounts of lighting were required for three-strip Technicolor.
For both cases, the prints were made by Dye Transfer process.
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