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  1. #1

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    AGFA Emulsion formulas

    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.

  2. #2
    Ian Grant's Avatar
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    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

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

    Emulsion.

  4. #4
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    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

  5. #5
    Ian Grant's Avatar
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    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

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    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

  7. #7
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    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
    There is no such thing as taking too much time, because your soul is in that picture. -Ruth Bernhard

  8. #8
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    Try the US Library of Congress Joe and look for the FIAT reports on Agfa technology.

    PE

  9. #9
    AgX
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    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.

  10. #10

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    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

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