AGFA Emulsion formulas

[Emulsion]

Hi,

Some previous posts mentioned WWII vintage Agfa emulsion formulas.

Does anyone reading the forum have any that they could publish? I am particularly interested in slow speed photographic film formulas.

Emulsion.

 

[Ian Grant]

Yes I have them. Many are still on microfilm & in the UK, but I have most of the paper emulsions here in the Aegean, some ready to post in the articles section.

Sean has said he will tweak that section to allow tables, which hasn't happened yet.

Ian

 

[Emulsion]

That sounds great Ian. Thankyou for offering this rare information. Another alternative to the tables might be to make scans or pdfs etc.

Emulsion.

 

[Photo Engineer]

I have already posted one formula that is a cross between the Agfa Lupex and Kodak Azo formulas here. Ian and I have exchanged notes in that thread on the subject.

Remember, all of these formulas assume the use of three grades of active gelatin, and also require the addition of chemicals to a final operation as well as an overcoat with ingredients. This makes the formulas quite unworkable in most modern home darkrooms.

I am trying to modify them to work in one concerted operation without overcoats and with all chemistry in one layer. I am trying to get these types of formulas to work with fixed amounts of sulfur added in oxidized gelatin.

So, while the old Agfa formulas will be quite useful, they will generally be slow, low in contrast and poor in keeping unless some fixup is applied.

PE

 

[Ian Grant]

Ron, I totally agree with your points. Back in the 70's/80's when I manufactured emulsion commercially I initially used active gelatins but switched to de-activated gelatin and added sulphur compounds. This gave better speed and contrast.

The old Agfa paper formulae are useful because it's fairly easy to see how different grade emulsions were made. As Ron and I have discussed in other threads some of the chemicals used are now banned for commercial use (cadmium salts).

Ian

 

[Photo Engineer]

Ian; I agree totally.

I would add the Lead and Mercury to that list, but also might mention that the small amounts of any of these used by individuals would pose no problem, as we commonly use them in other formulas for other purposes such as intensifiers and the like. In fact, the amount of Mercury used would be less than that used in a Mercury intensifier, I would think.

One of the problems with Agfa formulas is the use of a sulfur restrainer for stabilization. I have trouble with this, as it crystallizes in water and forms coating defects. I also find that Agfa formulas use a sulfite containing overcoat, and use egg white in the formulas to assist in gloss.

Many of these little things give the old materials their unique look which is difficult to reproduce in modern formulas. OTOH, modern baryta obviates their use in some cases or would inhibit their usefulness.

An example is the egg white, used to enhance gloss. Modern baryta is thicker and well calendered to give better gloss. Then again, modern baryta has fewer oxidizing agents and may not need the added sulfite.

This is part and parcel of the problems I'm facing and what I'm working on. It is also a problem for any non-chemist in seeing the formulas as written. They just don't work if you follow the instructions.

I would also add that many of the formulas are intentionally misleading as read. The people who passed on the formulas (Army personnel) were not engineers or chemists, and therefore the formulas were incomplete containing many comments such as "unbekannt" or 'unknown' in English and these gaps were not investigated or reported on.

Agfa had the habit of having unknown materials used, or keeping parts of the formulas secret back then, just as Kodak does to this day.

PE

 

[JOSarff]

Ian:

Do you know where (microfilm, microfische, online or hardcopy) the agfa formula's from posr world war II could be found. I'm mainly interested in the emulsion formula, but whatever you have should help.

Thank you

Joe

 

[Photo Engineer]

Try the US Library of Congress Joe and look for the FIAT reports on Agfa technology.

PE

 

[AgX]

Joe,

there are two "Agfa" historic archives out there.
One in Wolfen, Germany at the IFM museum, busy with the pre-war Agfa-Wolfen and the post-war Orwo.
The other in Mortsel, Flanders at Agfa, mainly busy with Gevaert but perhaps could be of assistance too.

 

[FRANOL]

Agfa developers

I have a old book with many formulas
(Agfa,Andersen,Windisch etc).There is 8 Agfa formulas for fine grain.I can scan those formulas but need 2-3 days to translate

 

[JOSarff]

Ron:

LC has 80 volumes of FIAT reports that have either poor or most no indexing. Some were published by the Department of Commerce post WWII. Others were published by Universities, U of Michigan among them. Do you have a more preciese thought on where to look?

 

[Photo Engineer]

Keyword search is Agfa. The report numbers mean nothing AFAIK. That is all I can suggest.

Sorry.

PE

 

[Ian Grant]

Ron (PE) has posted the Agfa Lupex formulae, here's the Brovira formulae from the F.I.A.T. report, apologies it's a low res JPEG but until Sean changes the Formula (recipes)/Articles section Tables aren't possible and this needs tables so you can see how the grades differ:

It's worth noting that the formulae weren't written & published by emulsion chemists, so there may be gaps & missing info. The F.I.A.T. reports were written by the military/Intelligence officers who didn't understand what they were writing.

However the Lupex & Brovira formulae give a good indication of how emulsions were made and the key differences between paper grades.

Ian

 

[Photo Engineer]

The interesting thing to me is that this is totally unlike the Brovira formulas that I have except for one point. The Rhodium Chloride concentration varies as a function of contrast. It goes up with contrast.

It only goes to show that there are many many Brovira formulas and many many variations of the Fiat reports. I would also add that for these formulas to function, they depend on active gelatins. This is a subtle point that a non-engineer would miss. The gelatin grade in my formulas varies with contrast as well. This would be missed in a read of the above if you had not had it pointed out. And so gelatin varies from "Hart to Weich" in the series above in my formula set.

PE

 

[Ian Grant]

Ron your point about engineers raises the major problem. These reports were written by army engineers, and they also detailed all the machinery used not just the formulae. For all I know my own father might have been involved, he had commanded an an IEME (Indian army Electrical & Mechanical Engineers) tank regiment during WWII and was in Germany from 45-47 after his British/Indian regiment became part of the Indian army.

Different companies would have drawn their own conclusions from the F.I.A.T. reports, Pierre Glafkides published the bare bones.

As you rightly say different Gelatin's would have made a big difference, and it's worth remembering that even Kodak films varied quite significantly depending on the plant, source of gelatin & water etc even into the early 70's. Tri-X dev times etc were different for US, Canadian or UK manufactured film.

Ian

 

[JOSarff]

I found that Los Alamos has a set (or almost a set) of the FIAT reports, so tomorrow I put on my lead thong and drive up the mountain. I'll keep you posted.

Joe

 

[Photo Engineer]

Ian;

Kodak engineers from Harrow, Chalon and Rochster used to argue what the proper shape of a curve for a paper or film should be and we ended up making 3 different products with the same name. Yes, I am familiar with this problem. Interestingly enough it was more in fine points of the final coating formula rather than ingredient mix.

As for the FIAT reports, yes, there are glaring problems which start with "hier unbekannt" (unknown here) in which chemicals came into Leverkusen or Wolfen from outside and no one knew what was in the jug. The same thing pertains at Kodak today. Many engineers do not know what is in a given ingredient. Beyond that goes the problem of temperature, addition time and other variables. Reading the formulas is like trying to read one of Wall's books. Very very cryptic and confusing and in both cases, for a specific reason. They wanted the best to be retained, not published. So, a formula in the reports is labeled "High Speed, Fine Grained Portrait Emulsion" and it by no means could be one! The only book I have found to give the parameters right is Baker. Second edition. But, even he fails to note the use (or non-use) of active gelatins.

PE

 

[Ray Rogers]

You lose a lot more than you imagine.

-----------
Hummmm...

All things considered, I think they did an amazing job.
Actually, the government(s) did enlist people from the industry and invited people, staff from eg. Kodak to come along; they would also, on occasion, visit and querry industry... something like, to the effect of "Is there anything you want to know?" before an interrogation.

But on a more sympathetic note (no hate mail please!) I must say I feel somewhat sorry for the German emulsion engineers, having their knowledge torn from them, striped naked and held up for the world to examine and peck at.

I have a lot of respect for their achievments, and yes, perhaps I feel some shame in having "stolen" their knowledge...

And, compared to what we have to be ashamed of today,
Well, we have a lot more to be ashamed of now.

In general though, (at least) Kodak (USA), was not particularly impressed with many of the facilities they found in use, having grown accustom to the more modern and efficient one back home.

X-Ray

 

[Photo Engineer]

It would be interesting to know what Kodak engineers spent time there! The data are so incomplete in most cases that it is hard to interpret and most high level Kodak engineers were involved in the Manhattan Project at the same time. So, they were elsewhere. I would have to downplay the Kodak engineers role in this.

PE

 

[Ray Rogers]

It would be interesting to know what Kodak engineers spent time there! The data are so incomplete in most cases that it is hard to interpret and most high level Kodak engineers were involved in the Manhattan Project at the same time. So, they were elsewhere. I would have to downplay the Kodak engineers role in this.

PE

Possibly. Probably. But there was at least some presence. I guess we could try and findout what their background really was... at this point I cannot confirm their expertise, but do you think anyone other than an engineer would have been sent? Also, it is possible that someone from the local Kodak was sent along... I don't know yet.

Ray

 

[2F/2F]

Ah, the good-ol' I.G. Farben days.....

I know it is about 20 years after the fact, but there is anything that might still be applicable to your search to be found in a 1961 Photo Lab Index, let me know, and I will transcribe it for you.

 

[Photo Engineer]

Actually, in answer to the formulas, Kodak engineers were pretty removed from these reports and the formulas were also very similar to Kodak formulas from about 10 - 20 years earlier. Kodak had advanced quite far from the materials and processes disclosed by Agfa. The advantage here went mainly to the Soviet block of nations who had virtually no photo industry at the time. At the time of transcription, Kodak was about 10 - 20 years ahead of Agfa, mainly due to the war which actually seems to have slowed some Agfa R&D.

The only advance made from these formulas noted by Kodak was the use of gold sensitization which gave one more stop in speed from a given emulsion. Other than that, Kodak was using advanced sulfur sensitizations with timed additions and the extrusion hopper coating system.

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.

So, there are wide variations in just the Brovira formulas themselves.

PE

 

[AgX]

PE, I doubt that "nations who had virtually no photo industry" as you put it, would gain that much from those reports as nations with an existant industry would have.

In the war time R&D went on. So far as literature looking back on that issue is concerned it seems that the gravity of work was done on colour those years.

By the way, in 1943 Kodak Eastman and IG Farben settled a patent issue, finally giving way for Agfacolor patents.
Business as usual...

 

[Photo Engineer]

In 1943, AFAIK, there was no business in the US conducted with Germany. IG Farben was kaput here. These companies subsidiaries in the US were nationalized and US subsidiaries over in Europe were nationalized by the Germans in their march across Europe. So, it cannot be said that technology moved one way. The Agfa scientists had all Kodak formulas taken from captured Kodak documents in Europe. People fail to point that out in the face of the FIAT reports, but it is a fact. In fact, in the face of the Kodak inactive gelatin work going back more than 10 years before 1940, it is surprising that Agfa still used active gelatins. Again, probably lack of R&D capability.

The fact that Lupex is almost identical to Azo and that Brovira is almost identical to Kodabromide is not a coincidence.

OTOH, Agfa R&D slowed almost to a halt due to bombing of plants and this is discussed in the FIAT reports BTW. Kodak R&D continued at a very high pace for IR films, UV films and for fine grain, high speed recon films for the US. Color was in high demand. Therefore at that time, Kodak was in production of Kodachrome film and an evolving variety of Kodacolor films and print materials.

Agfa made color materials that used the Fischer couplers, known for years, and used Brovira emulsions in their papers. Film emulsions for color were B&W emulsions. Kodak developed an entire new technology under Hanson and Vittum.

Konishiroku and Fuji used Agfa technology in direct technology exchanges to make their products and reverse engineered their Kodakcrhome products during the war. They both gradually converted to Kodak technology in the 60s.

PE

 

[Ian Grant]

It's quite probable that the F.I.A.T. reports didn't contain the most up to date Agfa emulsion information of the time. If Leica could mothball & hide the development work for the Leica IV camera, (which later became the M series), from the Nazi's and later the British & Russians then it would be very simple for Agfa to give the engineers what they thought they wanted.

Ian