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  1. #41
    dwross's Avatar
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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.

  2. #42
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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.

  3. #43
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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.

  4. #44
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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

  5. #45
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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

  6. #46
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    Quote Originally Posted by Photo Engineer
    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
    So what part of this was I expecting to be easy?

    MB
    Michael Batchelor
    Industrial Informatics, Inc.
    www.industrialinformatics.com

    The camera catches light. The photographer catches life.

  7. #47

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    Quote Originally Posted by Mustafa Umut Sarac View Post
    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.

  8. #48
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    Dry plates I assume? Therefore transportable.
    Michael Batchelor
    Industrial Informatics, Inc.
    www.industrialinformatics.com

    The camera catches light. The photographer catches life.

  9. #49
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    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

  10. #50
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    Quote Originally Posted by 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
    And I know for a fact that I'm not the only process control guy around here.
    Michael Batchelor
    Industrial Informatics, Inc.
    www.industrialinformatics.com

    The camera catches light. The photographer catches life.

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