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On the brink

Photo Engineer

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Well, two things on the brink really.

1. I have managed to order some samples of the biocide that Kodak uses for preserving gelatin and emulsions. If it works out, then this will allow emulsion keeping and gelatin keeping before coating to be increased by nearly a year or more. This will be a great economical benefit to workers in this area.

2. I have two samples of chemicals coming that will allow me to make my first color coatings. I am preparing to make 3 sheets of C/M/Y coatings on film with proper sensitization, so that I can superpose them and prove the concept. This was how Mannes and Godowsky got started. If it works, the final formula will be in the book. (Well, an outline of a thought experiment is there already, but having the real thing will be better)!!!! Don't you agree?

Anyhow. One emulsion in the can needing about 10 experiments to find out the "sweet spot", one emulsion (t-grain) to make in a few weeks, and the color emulsion when I get the chemicals.

Oh, I have worked up a cubic bromide emulsion and was wondering if anyone thinks that should be in the book as well. Opinions welcome.

I'm still working.

PE
 
This all sounds fantastic, Ron.
 
Sounds fantastic. I'm very pleased that you have decided to include the basic concept for color materials.

Cubic emulsions are used in low-speed, very fine grained print films, correct? It might be quite interesting too. Having many choices is a good thing so why not, if you have it ready. It would also demonstrate the differences in making as an example.

Keep going!
 
What is the current shelf life of the emulsions you are using, Ron? And will this work for plates as well as paper emulsions?
 
HRST;

Cubics can have any use you want, depending on size and Iodide content!

Chris;

Current emulsions keep for a year or so in the fridge and gelatin keeps for about 6 months. The new stabilizer (not Thymol) will extend that by up to a year at minimum. This assumes about 4 - 10 deg C. You should not freeze an emulsion or gelatin in water.

PE
 
Awesome! Seriously PE, your a hero.

Just wondering, how long lived is the images made from c/m/y as you describe? I wish you the best of luck making it
 
alexhill said:
Awesome! Seriously PE, your a hero.

Just wondering, how long lived is the images made from c/m/y as you describe? I wish you the best of luck making it
Click to expand...

I will be using an Azo dye, so it will be on the order of Ciba/Ilfochrome. If it works that is! I may fail.

In addition, it will probably have to be coated on film or Yupo (or similar) as they are the only supports that will survive the dye bleach process.

PE
 
Outstanding news, Ron!

I'd like to see the all of this new work included in the book. Gives us much more to experiment with, for certain. Who knows where this will all lead....


Bob M.
 
I'd rather see the B&W emulsions finished and any color emulsions could be in Volume II. There's a lot of color theory that should be added to a second volume in addition to just how to make a color emulsion.
 
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Kirk;

At the present time, IDK if there will ever be a volume II or even a second edition.

PE
 
No preorders at this time. I am still working on the method of distribution and thus no way to take preorders.

Sorry.

PE
 
Kirk, Would your perfected formula for a T-grain emulsion be included in Volume II ?
Ron, Don't you think that glass plates would survive the dye bleach process ?
Bill
 
Bill;

Glass plates will survive, but my first effort will require aligning 3 separate color positives to test the system and you cannot register glass plates.

PE
 
Very exciting, I'll wait no matter how long for such a book

I'd love to see the colour stuff, I was looking over some of the dye bleach formulas or starters given and that Azochrome patent mentioned in some other thread, and it kinda seems like the chemistry for it is difficult to get your hands on.

If there's no Vol II or 2nd edition, I request an inclusion of colour, of course the more you can include, the merrier, though I understand that choices need to be made for time to get any of it done in the first plac.
 
For those interested.

A simple color coating experiment:

Coat 50 mg/ft square of the Azo dye Chicago blue (or any suitable Azo dye actually, for example Tartrazine will give a yellow image). In this mix include the equivalent of 50 mg/ft square of Silver as Silver Halide. The gelatin should be at about 250 mg/ft square.

Coat on a good paper support or film with a high level of formalin hardener.

Allow to cure for up to 1 week for best hardness.

Expose
Develop in D-19 for about 1 minute.
Rinse for about 30" in running water.
Bleach in a dye bleach solution with Phenazine at about 100 mg/L and sulfuric acid to pH 1.0. until the image clears.
Rinse for about 30" in running water.
Fix in any fixer
Wash normally for a paper or film.

Dry

This should give you a positive image in color based on the chosen dye. Chicago blue will be bluish and tartrazine will be yellowish.

PE
 
This sounds suspiciously easy and simple.


Where do you get your phenazine from?


Silly question.. but does this mean one could use other random food dyes? Like Tumeric?... or super market food colouring accounting for the dilution?


edit Im guessing that's a big no, and only what I see here - http://en.wikipedia.org/wiki/Category:Azo_dyes

I just fond that Queen's Green Food Colouring contains E102 (tartrazine) mixed with E133, I think the yellow food colour is E107 as well, which wiki says is an azo dye.. alright part way there to actually attempting something..

Further looking on the bottle says it also contains some citric acid and sodium benzoate..
 
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Makes me wonder too, could vegetable matter, like saffron or yellow primrose, be used to create easy-to-make diazo type printing paper?
I know van der Grinten (Océ) used Primulin to start them on their way to simple and easy to use copying papers.
 
Black also containes E102 (along with E123 and E133)

O/T: E123... 'but since 1976 it has been banned in the United States by the Food and Drug Administration (FDA) as it is a suspected carcinogen. The FDA showed a significant increase in cancer among aged female rats that had been fed large doses of the dye.'

...err why do we still have it in Australia? Also listed as 'forbidden' and known to cause disease beyond any doubt on the E number page on wiki.

edit: Back to the green food colouring, E102 is listed first, and 'total dye stuffs' is 2.1%, so I figure it should contain the majority of that 2.1%, so >1.05%... so ~0.5ml per ft square perhaps?

I wonder if they do work, will it stay green? or use only the tartarzine part and be yellow? Hmm.
 
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...err why do we still have it in Australia?

Because, in Australia all molecules are "mirror images" of what they are in the "real world". L is D and D is Q or Z or something in Sanskrit.
Bill
 
Well, the redox reaction between silver and dyes is best undertaken with azo dyes for reasons of stability to the acid pH needed and the post process dye stability. So, most other dyes will not do for this.

Also, most azo dyes contain sulfonic acid moieties that help them dissolve in water and help them stay in the gelatin matrix.

And, I've said that the future of color may be dye bleach due to its inherent simplicity, but don't be fooled. Making the multilayer is going to be a beast. I will be superposing 3 sheets to get a tripack when I do it, I will not be going for the multilayer on one support.

The multilayer invoves:

Overcoat/Blue sensitive Silver Halide/Yellow dye + Blue sensitive Silver Halide/absorber dye and scavenger/Green sensitive Silver Halide/Magenta dye + Green sensitive Silver Halide/scavenger/Red sensitive Silver Halide/Red sensitive Silver Halide + Cyan dye/support. That is about 9 layers.

With good dyes and emulsions, you can omit the interlayers and overcoat sacrificing color purity. You can eliminate the extra Silver Halide only layers sacrificing good contrast control.

PE
 
You make the tinted monochrome version sound easy and simple at least.


If I wanted to experiment as quickly as possible, I'm guessing buying a premade liquid emulsion might be the best idea.
 

I doubt i will ever make a good, or even mediocre, emulsion maker. Have to do a lot of brushing up on chemistry too. And i really mean a lot.
But it's all fascinating stuff, this!
 
You can be a great emulsion maker without knowing chemistry, as long as you follow a tried and true recipe!

Give it a go.

PE
 
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