preparation of photosensitive coatings for Lippmann photogra

This is a forum exploring Lippmann photography.
laywomen

preparation of photosensitive coatings for Lippmann photogra

Post by laywomen »

Hello,
we are two chemists, who want to repete the Lippmann photography. We already found a receipe for the photosensitive emulsion ("the preparation of ultra-fine grain photographic emulsions" by B. H. Crawford, National Physical Laboratory, Teddington, Middlesex, 1954) and we prepared some emulsions, but we still have problems with the process of coating and washing, drying and using these coating for Lippmann photography. Because mecury is not available, we want to use Al mirror instead of Hg. So fare done experiments with our camera obscura brought us only black and white negatives.
Can somebody help us to solve our problem!
Which are the conditions for preparation the coatings on glass substrates? Under which circumstances we should dry the coatings in order to obtain very transparent coatings (usable for Lippmann)? How high must the transparency of the coating be? How shall be do the development? So far, we used Rodinal (Agfa).

Many thanks in advance!

Best regards,
laywomen
Joe Farina

preparation of photosensitive coatings for Lippmann photogra

Post by Joe Farina »

There is a longer paper (a booklet actually, 20 pages) by Crawford called "Small-Scale Preparation of Fine-Grain (Colloidal) Photographic Emulsions." (1960) It goes into more detail than the 1954 paper. I can send you a .pdf copy if you like.
laywomen

preparation of photosensitive coatings for Lippmann photogra

Post by laywomen »

Hello Joe,

thank you very much for your fast answer! It would be nice if you could send us a pdf copy of this booklet. We are very excited.
Thank you, we appreciate it.

Regards,
laywomen
Hans

preparation of photosensitive coatings for Lippmann photogra

Post by Hans »

I am also interested. Could you send one to me too please?
Martin

preparation of photosensitive coatings for Lippmann photogra

Post by Martin »

laywomen wrote:Hello,
we are two chemists, who want to repete the Lippmann photography. We already found a receipe for the photosensitive emulsion ("the preparation of ultra-fine grain photographic emulsions" by B. H. Crawford, National Physical Laboratory, Teddington, Middlesex, 1954) and we prepared some emulsions, but we still have problems with the process of coating and washing, drying and using these coating for Lippmann photography. Because mecury is not available, we want to use Al mirror instead of Hg. So fare done experiments with our camera obscura brought us only black and white negatives.
Can somebody help us to solve our problem!
Which are the conditions for preparation the coatings on glass substrates? Under which circumstances we should dry the coatings in order to obtain very transparent coatings (usable for Lippmann)? How high must the transparency of the coating be? How shall be do the development? So far, we used Rodinal (Agfa).
Principally, there are plenty of files regarding Lippmann photography in the Wiki section here. It looks like though they're not accessible right now.
Send me a private message if you need one of these files urgently...

How do you plan to coat your Al mirror? I assume it has to be pre-treated with some release agent in order to be able to remove the exposed emulsion from the reflector.

As for coating glass plates etc., there's plenty of information in the DCG section.
And regarding the coatings, they of course need to be of utmost clarity (transparence). I guess this is not so much the drying condition but rather a question of the quality of your emulsion (grain size, fog etc.).

Rodinal developmer is based on p-amidophenol and lots of sodium sulfite, I believe. I've never heard this developer to be used in the context of Lippmann photography.
Darran Green, who makes beautiful Lippmann photos, uses a colloidal GP-2 developer.
Joe Farina

preparation of photosensitive coatings for Lippmann photogra

Post by Joe Farina »

Laywomen and Hans, please send me a private message with your email address, and I will send it along.
Colin Kaminski

preparation of photosensitive coatings for Lippmann photogra

Post by Colin Kaminski »

I ran out of room for the pdf's on the Forum server. I am in the porcess of moving them to a new server and they will be back soon. Sorry for the delay I am spending all my free time trying to get a house remodeled.
Danny Bee

preparation of photosensitive coatings for Lippmann photogra

Post by Danny Bee »

Colin Kaminski wrote:I ran out of room for the pdf's on the Forum server. I am in the porcess of moving them to a new server and they will be back soon. Sorry for the delay I am spending all my free time trying to get a house remodeled.
Colins i have alot of free space 5 gig, we can work something out here.
Tom B.

preparation of photosensitive coatings for Lippmann photogra

Post by Tom B. »

You might also consider coating glass plates in the traditional way and substituting another liquid metal for mercury, such as gallium or a gallium/indium alloy:

Info here: http://www.indium.com/TIM/solutions/liquidmetal.php
Small quanities available here: http://www.scitoyscatalog.com/Merchant2 ... ory_Code=H

It's remotely possible that there might be practical difficulties such as chemical incompatibility or permanent wetting/discoloration of the gelatin, but it seems worth a try.
laywomen

preparation of photosensitive coatings for Lippmann photogra

Post by laywomen »

At the moment , we read a lot of literature and also old threads.
Can sombody tell us, what does "TEA" mean? Is somewhere, here in the forum, a page with all the used abbreviations?
Are the developer (e.g. GP-2, CW-C2) commerially available or do we have to mix it on our own?
For Lippmann photography process, is there a bleaching step also necessary? What does the bleaching process effect?
Can we use a standard fixing solution for black and white photography?
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