Emulsion Makers Book Club, Selection One: Photographic Emulsions

[michaelbsc]

PE, are you serious that I can probably make pan 400ISO sheets at home given the techniques?

And that I can make a color sheet film as well? At what speed? I assume this is a negative without orange mask?

Yes, you could probably make an ISO 400 emulsion, but I think that you would find that making glass plates would be better than film.

The color material would probably be a dye bleach material and would give slides. They would be very grainy and the film would be slow. A coupler based system would be harder to devise due to the need for custom chemistry. The couplers are just not available. A Kodachrome like product would be easier to make in some respects but harder to process.

PE

So what part of this was I expecting to be easy?

MB

 

[Q.G.]

Can you copy and write [...]

dwross,

I too don't want to sidetrack this thread, but a word of warning: those two highlighted words spelled a bit differently, and page 4 of the scanned book, can get you in serious (and expensive) trouble.

 

[michaelbsc]

Dry plates I assume? Therefore transportable.

 

[Photo Engineer]

Sometime about 1630, Samuel Pepys had a golf ball sized stone removed from his bladder by surgery. He was one of the few people who survived surgery in those days. If you had to have a stone removed, would you choose the surgical method used on him, or a modern method?



I know, I know, this sounds stupid, but the fact remains that all works published on emulsion making that are dated before about 1940 have a similar relationship regarding both theory and practice to the example in my first paragraph. Even the FIAT and BIOS reports show emulsions that give some very nice products but are quite primitive. You will find that the old reports described in German, use the word "gekippt" which means that the ingredients were "tipped" or "dumped" into the reactor to make an emulsion. Well, one of the great advances that introduced constant and repeatable speeds was the use of pumps!

Ok, then take this a step at a time. A better mixer gave better uniformity. Subsurface addition of ingredients removed the effects of foam, dual running of salt and silver gave better curve shape. Baker and Wall, and even Carroll knew nothing about these things in 1940! Can you do any or all of these in your darkroom? Of course you can! And that is part of my point here.

PE

 

[michaelbsc]

Sometime about 1630, Samuel Pepys had a golf ball sized stone removed from his bladder by surgery. He was one of the few people who survived surgery in those days. If you had to have a stone removed, would you choose the surgical method used on him, or a modern method?



I know, I know, this sounds stupid, but the fact remains that all works published on emulsion making that are dated before about 1940 have a similar relationship regarding both theory and practice to the example in my first paragraph. Even the FIAT and BIOS reports show emulsions that give some very nice products but are quite primitive. You will find that the old reports described in German, use the word "gekippt" which means that the ingredients were "tipped" or "dumped" into the reactor to make an emulsion. Well, one of the great advances that introduced constant and repeatable speeds was the use of pumps!

Ok, then take this a step at a time. A better mixer gave better uniformity. Subsurface addition of ingredients removed the effects of foam, dual running of salt and silver gave better curve shape. Baker and Wall, and even Carroll knew nothing about these things in 1940! Can you do any or all of these in your darkroom? Of course you can! And that is part of my point here.

PE

And I know for a fact that I'm not the only process control guy around here.

 

[Photo Engineer]

Dry plates I assume? Therefore transportable.

Absolutely dry plates. Keeping at the present time is about 1 year for the uncoated emulsions and 1 year for the coated materials. I can do better, but there is just so much time to experiment and write.

PE

 

[Photo Engineer]

And I know for a fact that I'm not the only process control guy around here.

I've found that you don't need full control with feedback loops. You just need a high impedence meter with the right electrodes and a syringe of salt to poke the vAg back into control. You see, salt rate needs to rise over an addition just to keep the salt in balance. The vAg is the measure of salt, and therefore you can just add salt from a syringe dropwise to keep the millivolts constant with your needs.

No computer is needed.

PE

 

[Mustafa Umut Sarac]

Ron ,

I found your old post archives.

Here is the Brovira Formulas Link :

 

[Hexavalent]

I've found that you don't need full control with feedback loops. ...

PE

But, a geek like me cannot resist the beauty of a well-tuned analog PID controller

 

[Photo Engineer]

The post above on Brovira was not mine. Both Ian Grant and I posted Brovira variants in a thread here about a year or so ago.

I would add that the formulas above do NOT explicity give the types of active gelatin used. Each grade of early Brovira and Kodabromide used a different type of gelatin tailored for the contrast grade. So the formulas above would either have to use old style gelatin blends or be revised for modern chemical sensitization methods. Also, Brovira did use Rhodium Chloride IIRC.

PE

 

[michaelbsc]

Dry plates I assume? Therefore transportable.

Absolutely dry plates. Keeping at the present time is about 1 year for the uncoated emulsions and 1 year for the coated materials. I can do better, but there is just so much time to experiment and write.

PE

Ok, so how many pounds, gallons, ml, or grams is reasonable to make in a batch? And how many square inches or square cm will that coat on average?

And how do you coat? I'm familiar with costing flexible materials using a jet nozzle, buy that's beyond a common darkroom. Something like pouring a collodion?

 

[Photo Engineer]

I have made from 5g or 100 ml to 150g or 3000 ml with no problem. These are slower speed. I am still working on the high speed emulsions which can only be made at about the 1/2 liter to 1 liter scale. I coat using my coating blade which has been discussed here over and over. I have 1 for paper, 1 for film and 1 for plates.

PE

 

[Mustafa Umut Sarac]

Ron ,

I found British and American documents from that time range as a list at internet. There are every kind of technology reports on engines to chemicals.
If I order the copies of Agfa documents , would I be able to see the gelatin formulas or what is the source of Brovira Gelatin preperation technology ?
Do you know them or Ian knows them ?

Thank you ,

Umut

 

[Mustafa Umut Sarac]

Ron , you posted 2 years ago ,

Kodak was using the oxidized gelatin in the 40s while Agfa formulas still used 3 - 4 grades of active gelatin. This is not seen in Ian's formulas above, so I did some research...

Brovira Extra Hard = Gelatine mittelreifend
Brovira Hard = Gelatine mittelreifend
Brovira Normal = Gelatine mittelreifend
Brovira Special = Gelatine kraeftigreifend + Gelatine schwerreifend + Gelatine mittelreifend
Brovira Weich = Gelatin kraeftigreifend + Gelatine schwerreifend

A German - English dictionary will tell you that Reifend = Bloom, and you may wish to equate this with Bloom Index used today to classify viscosity and strength in gelatin, but these terms are not related.

My Brovira formulas also include a spectral sensitizing dye (hier ist unbekannt - unknown at the plant) and an organic stabilzer added to the emulsion just prior to the coating operation.

 

[Q.G.]

Ron , you posted 2 years ago ,

Kodak was using the oxidized gelatin in the 40s while Agfa formulas still used 3 - 4 grades of active gelatin. This is not seen in Ian's formulas above, so I did some research...

Brovira Extra Hard = Gelatine mittelreifend
Brovira Hard = Gelatine mittelreifend
Brovira Normal = Gelatine mittelreifend
Brovira Special = Gelatine kraeftigreifend + Gelatine schwerreifend + Gelatine mittelreifend
Brovira Weich = Gelatin kraeftigreifend + Gelatine schwerreifend

A German - English dictionary will tell you that Reifend = Bloom, and you may wish to equate this with Bloom Index used today to classify viscosity and strength in gelatin, but these terms are not related.

My Brovira formulas also include a spectral sensitizing dye (hier ist unbekannt - unknown at the plant) and an organic stabilzer added to the emulsion just prior to the coating operation.

"Reifen" is (among other things) to ripen.

 

[Photo Engineer]

Reifen is indeed ripen which is used as a term with active gelatin which contains the natural sulfur containing amino acids which break down into allyl thiourea when heated with silver halide. This is why all old formulas MUST be converted to be used with modern gelatins or you just do not get the speed nor the contrast!

PE

 

[AgX]

"Reifen" is also used in conjunction with chemical sensitization when using in-active gelatin.

 

[Kirk Keyes]

Ok, so how many pounds, gallons, ml, or grams is reasonable to make in a batch? And how many square inches or square cm will that coat on average?

And how do you coat? I'm familiar with costing flexible materials using a jet nozzle, buy that's beyond a common darkroom. Something like pouring a collodion?

Micheal - you should sign up (and anyone else interested in learning more about this from a hands on viewpoint) for Denise Ross' classes at the Photographers Formulary next June (2011). Denise is an excellent teacher, and she makes the most beautiful handmade silver gelatin papers that I've ever seen. She's giving one class on papers, and one on plates.

 

[Kirk Keyes]

I don't think any one person, or even a small group of people will be able to match the level of technology that is in todays commercial color film products. But we as home emulsion makers can still make marvellous papers and B&W film/plate emulsions.

We just can't compete with the amount of applied science that goes into these things. Which one of us is going to spend the hundreds of thousands of dollars for equipment and get the radiation licenses needed to make and operate a silver content meter to measure the amount of silver that is applied to our film as we run our home make emulsion coater?

But we can still do great things, as individuals and through groups like this.

 

[Kirk Keyes]

Here's my contribution to the book club:
"Photographic Emulsions" by E.J. Wall (1929)
http://www.keyesphoto.com/KDKtech-E._J._Wall-Photographic_Emulsions.html

Again - it's old and needs to be read with a grain of salt (preferably a silver halide...).

 

[Photo Engineer]

I saw a "hand held" X-Ray fluorescence analyzer on Wednesday that was attached to a simple microscope. Image the film and then point the analyzer at the spot, which is about 1mm square or less, and you get the amount of whatever metal you are looking for be it Silver, Mercury, Lead etc.... These units cost a bit, but are so easy to use that anyone can now do QC on their hand coatings. Well, I don't think we need one of these, but I mention it to show it is possible. No radiation license is needed AFAIK.

PE

 

[Kirk Keyes]

Ron - all the hand held X-Ray Fluorescence meters I've seen (about the size of an old Geiger counter) need certifications for use. They usually have a radioactive isotope as the source of the x-rays.

 

[Photo Engineer]

Could be. This one was about 1.5x the size of a Hanna pH meter. You know the ones I am referring to. Pretty small unit. It was connected to a power supply that was out of sight from me. The cable was not very large in diameter. It had 2 radiation trefoils on it that I assumed were there due to the X-rays rather than to a radio-isotope. I should have thought to check.

PE

 

[Mustafa Umut Sarac]

I think these are work as handheld x ray spectrometers. No need of certificates , source is semiconductor.

 

[dwross]

I don't think any one person, or even a small group of people will be able to match the level of technology that is in todays commercial color film products. But we as home emulsion makers can still make marvellous papers and B&W film/plate emulsions.

We just can't compete with the amount of applied science that goes into these things. Which one of us is going to spend the hundreds of thousands of dollars for equipment and get the radiation licenses needed to make and operate a silver content meter to measure the amount of silver that is applied to our film as we run our home make emulsion coater?

But we can still do great things, as individuals and through groups like this.

Kirk,

Thank you for putting things into perspective so eloquently (and for the workshops plug ). I can't add much to the core of your statement, but I will give a try at an addendum. I was busy all day yesterday with a back-breaking, braindead, non-photography task, and had nothing but time to think about the situation here.

It's long been a puzzle to me that Ron continues to make basic emulsion making into a task that is beyond reach of mere mortals. There seems to be a resistance to evidence that defies the facts -- that gorgeous, extremely useful emulsions are being made, today, with today's materials and knowledge. And, it doesn't take a chemistry degree, professional lab equipment or a big budget. The embryonic cynic in me has wanted to blame it on trying to prime the pump for book/DVD sales (whenever that may be). Yesterday, I came to a more charitable viewpoint -- at least for Ron, if not for Kodak.

George Eastman started Kodak right out as a monopoly. Not only was commercial competition aggressively, and sometimes ruthlessly, quashed, but so too was 'competition' from do-it-yourself'ers. The motto of "you push the button, we do the rest" was there from the beginning. Kodak pushed a corporate philosophy of infantilizing its customers, with a brilliant campaign that involved both carrot and stick. After what is literally now generations of the honing of that philosophy, how can an engineer who worked in the glory days of Kodak's empire even consider that some of us not only can, but want to do things ourselves? And this includes research, both literature and lab. It's a transparent aluminum wall of paradigm disconnect.

No problem, and if I'm going to run down the rabbit hole with Star Trek references, I'll finish with a classic: infinite joy in infinite diversity.

I think we can make a lot of progress understanding silver gelatin emulsions if we respect each other's goals. Some of us are interested in understanding the advanced chemistry and technology of contemporary, high-tech emulsions, with no intention of actually making one. Totally understandable. But some of us are artists and just want to make beauty. Hopefully, we can discuss emulsion making from that point of view also, with the goal of discovering the possibilities and answers, rather than dwelling on the difficulties and questions.

d