Ray Rogers, the link didn't work? The link basically goes to the last relevant page, you need to go back several chapters for the goods. There's some really good stuff in there. Apparently, in theory, a Lippmann should transmit the complementary colors of what it reflects. R Shaffer, do you notice this at all in your examples?
Also, it says that pictures made w/o the mercury reflector are "necessarily dull". Bummer considering that's what we're doing. Lastly, it talks about the possibility of reproducing Lippmann photographs, particularly by projection onto another plate, which is the first I've heard of this. I don't think it's effective in practice however. Anyways, I highly recommend reading it, it's the best historical overview on the topic that I've read to date.
And lastly, I can only say that I strongly encourage Lionel1972 to get with Ray Rogers and translate those files. That would be truly incredible, and might make these papers available to English speakers for the first time! I'll do anything to facilitate, although I don't know what that would be, other than applauding from the side lines.
I've just browsed one of the French files : "Manuel de photochromie interférentielle" by A. BERTHIER puplished in 1895. It confirms the "necessarily dull" aspect of pictures made without mercure reflector; it gives different receipes to make a proper emulsion, how to apply it, how to modify it in order to make it faster without losing the colors. It also hints to some directions for amateurs to experiment and find ways to improve the process (like using 2 different types of emulsions one on top of the other) or using wet collodion. Translating all this is quite a lot of work, I didn't realize that at first. I might need some help depending on how many of those papers needs to be translated. Maybe I'll make a post on the French forum.
Last edited by Lionel1972; 06-14-2010 at 11:59 AM. Click to view previous post history.
Sure, whatever I can do to help, however, I don't speak French unfortunately.
Indeed, I thought your volunteering was quite ambitious!
However, as Ray Rogers said, perhaps just typing out the text in French would make it more suitable for OCR (optical character recognition) and thus, automated translation.
Let me know. And very interesting, using 2 diff. types of emulsions stacked!
Automated translation is still rather poor. French friends and I have had a good laugh over some translations of Kodak reports that were weird to say the least. Technical terms are the worst.
Please take a look at GALLICA (http://gallica.bnf.fr/). Some of the articles I had put online on the holography forum used to be available at their site. In the meantime (I may have stopped looking for Lippmann resources around 2004 or so) they put a bunch of interesting books/papers touching on Lippmann photography online. I'm particularly thinking of the BULLETIN DE LA SOCIETE PHOTOGRAPHIQUE - incidentally, that journal is a real treasure for anyone interested in "alternative photography".
Originally Posted by Lionel1972
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Ray, I'll try to upload those files on a different server soon.
Originally Posted by Ray Rogers
My apologies for the poor quality of those files - they're mostly copied from old books (in poor shape) at the library.
Speaking of translations, you might try to make the German texts available to a broader audience. For example, Neuhauss' journal, which I transcripted, is there in a purely digital format.
I guess the problem is a "holographic" one. In order to get those complementary colors the recording medium needs to have high index modulation (without making it overly complicated, it means a very thin recording layer can produce high diffraction efficiency).
Originally Posted by holmburgers
That's exactly the point. Speaking of holography (my main area of interest) again, more precisely of the making of a reflection hologram, there's a correlation between the beam ratio (the beam hitting the plate directly and the one from the rear side) and diffraction efficiency. In order to get high modulation the beam ratio ideally has to be 1:1. Obviously, in the Lippmann case without a mercury (or alike) reflector this is difficult to achieve.
Originally Posted by holmburgers
In practice, I've seen the complementary color thing in holography only on one home made silver halide emulsion that had quite a high amount of silver. That would make sense, given the high refractive index of silver bromide.
With high index modulation recording materials like DCG (dichromated gelatin etc.) however, that effect can be achieved pretty easily.
I agree with PE on his doubts about automated translation of those old technical papers.
But first give me a list of priority for the papers you think would be most interesting and I'll try to start with them soon.
"The nineteenth century began by believing that what was reasonable was true, and it wound up by believing that what it saw a photograph of, was true.
" - William M. Ivins Jr.
"I don't know, maybe we should disinvent color, and we could just shoot Black & White.
" - David Burnett in 1978
"Analog is chemistry + physics, digital is physics + math, which ones did you like most?
I studied my first set of plates a fair bit before painting the back black. Mostly they looked red and I included an image in my post after my initial modest success. I looked back thru the images I made of the plates before blacking and one may be showing a complementary color. It was a heavily overexposed plate that shows strong blue ( solarized ) in the blacked plate and strong red transmitted in the same locations. I attached a copy of the image. But I have not noticed any other similar effects.
Originally Posted by holmburgers
As far as the plates being dull. Well that is OK by me. When I wanted to try this process out, it was because I was fascinated by the idea that a light wave could be recorded in an emulsion. And the proof of this was a color image reflected back at me. Incredible!!! That I could, with my camera and in my laundry room, record something that is only 200nm to 375nm in size.
As a comparison the average human hair is 0.1mm and you would have to divide that human hair 500 times to get the half wave length of violet light.
Science geek fun more so than photo geek fun, but add them together and that is seriously geeky fun
Last edited by R Shaffer; 06-15-2010 at 09:32 AM. Click to view previous post history.
Reason: forgot image