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  1. #41
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    There are several points here to address.

    Knowing the ingredients does not tell you anything about how or when they got into the film. AgX is correct!

    Analysis may not tell you what all is there, especially when some trace elements are there at very low levels. You cannot, a priori, say if it is there deliberately or is there as an impurity.

    I have read the Brovira formula and have devised a Kodabromide like formula of my own. There is little similarity between the two formulas. The latter, mine, will be included in my book. I did not include the Brovira formula. My formula is doped with Rhodium Chloride at about 10^-6 moles of Rhodium per mole of silver. You can see how low that level is and how difficult it would be to detect in most analyses.

    Both Kodak and Agfa used Rhodium salts for contrast control just as I do in my formula. Nowdays, Kodak uses organic compounds which were unavailable to me.

    I have no information as to what plans might be in place if Kodak stops production of analog products, but I would ask the same question of Fuji and Ilford as a rhetorical question. After all, where really are the Agfa formulas for their color papers and films and what might happen to the Ilfocolor formulas if they stop production?

    PE

  2. #42
    Mustafa Umut Sarac's Avatar
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    PE ,

    Where did you find the Brovira Formula , is it patent , open or archive document ?

    I think testing different batches of same paper tells what is impurity , what is for real.

    Umut

  3. #43
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    Quote Originally Posted by Mustafa Umut Sarac View Post
    Where did you find the Brovira Formula , is it patent , open or archive document ?
    'Photographic Chemistry', Volume One, by Pierre Glafkides, 1957, pp 342-343. Five grades: Extra Hard, Hard, Normal, Special, and Soft.

  4. #44
    Mustafa Umut Sarac's Avatar
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    dwross ,

    Can you copy and write here what is reported at these two pages

    Umut

  5. #45
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    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?
    Michael Batchelor
    Industrial Informatics, Inc.
    www.industrialinformatics.com

    The camera catches light. The photographer catches life.

  6. #46
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    Quote Originally Posted by Mustafa Umut Sarac View Post
    dwross ,

    Can you copy and write here what is reported at these two pages

    Umut
    The Glafkides book, at least the chapters on emulsion making, are next but one on my scanning and posting schedule for TLF. I'm currently working on 'Successful Negative Making', by T. Thorne Baker.

  7. #47
    Mustafa Umut Sarac's Avatar
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    Thank you dwross.

    I am waiting your Agfa Scans.

    Umut

  8. #48
    Mustafa Umut Sarac's Avatar
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    AgfaPhoto is the new company responsible for the photographic products.

    I sent to a message asking archive research.

    Monday or Tuesday answer could appear at my mailbox and I will be here.

  9. #49
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    Quote Originally Posted by Mustafa Umut Sarac View Post
    PE ,

    Where did you find the Brovira Formula , is it patent , open or archive document ?

    I think testing different batches of same paper tells what is impurity , what is for real.

    Umut
    I had access to the BIOS and FIAT reports of WWII. They are at the GEH, RIT and EK libraries IIRC. The formula has changed little over the years except for keeping and reciprocity chemistry.

    PE

  10. #50
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    Quote Originally Posted by michaelbsc View Post
    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

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