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  1. #151
    holmburgers's Avatar
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    From here

    Color-sensitising by Bathing, by T. Thorne Baker, pgs. 83-86, Process Engraver's Monthly, Volume 14, 1907.

    "The following dyes may be used for bathing where red sensitiveness is wanted:-

    Pinacyanol (Fuerst)
    Pinachrome (Fuerst)
    Orthochrome T. (Fuerst)
    Homocol (Bayer)
    Pericol (Bayer)
    Isocol (Bayer)

    With the exception of pinacyanol and pericol, all the above greatly enhance the green-yellow sensitiveness as well, and hence render the plates panchromatic, though the only dye which gives anything approaching an even sensitiveness throughout the spectrum without marked maxima and minima is homocol plus ammonia, and where ammonia can be left out of the question, I strongly recommend it, as plates treated with an isocyanine derivative plus ammonia keep indifferently, and rapidly deteriorate in color-sensitiveness."
    If you are the big tree, we are the small axe

  2. #152

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    Quote Originally Posted by holmburgers View Post
    This table is reproduced from Hans Bjelkhagen's Silver-Halide Recording Materials: For Holography and Their Processing. Available on Google Books.

    In a nutshell, Lippmann used cyanine & chinoline red, Vatenta used cyanine & erythrosine, and Ives used isocol, erythrosine & pinacyanol.

    also...

    Pinacyanol (1:1000 alcoholic solution) 4mL
    Orthocrom T (1:1000 alcoholic solution) 4mL
    Acridine orange (1:500 alcoholic solution) 4mL

    The particular sensitizing dyes mentioned above and their combinations were discovered and used by H. Lehmann to produce the best correct-color sensitivity ever achieved in Lippmann photography. However, he kept secret his good formula for Lippmann plates and it was not revealed until after his death. If one wants to try this old photographic technique today, these dyes are definitely the first choice. (emphasis mine)
    Hi Chris
    When I was doing holograms I used eosin (aniline red) for green lasers, methylene blue for red, and glycerin for the electron donor in gelatin. I tried acridine orange, but don't remember anything special with it.(I think they came out violet) It also has to be washed out of the plate with alcohol,water alone won't do it.After coating they were dried out,and dipped in ascorbic acid to sensitize and let dry over night before use. They were not light sensitive until after the dip
    Some really funny things happened with those holograms
    If you can get the book do so . It is a gold mine of info,except I get lost when he sorts out what the types of bleaches are used for
    rob

  3. #153
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    1,1'Diethyl-2,2'-dicarbocyanine Iodide from the OP list is available at Sigma Aldrich
    All this has happened before, and all this will happen again.

  4. #154

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    Is there a difference between 1,1'-diethyl-4,4'-carbocyanine with iodine vs bromine vs chlorine?

  5. #155
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    Yes, there is.

    You should not use the Iodide salt with a bromide or chloride emulsion. You should not use a bromide salt with a chloride emulsion. There are rules for counter ions when making emulsions.

    PE

  6. #156
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    What kind of emulsion would you use an iodide form cyanine dye with? There are a number of them on the list of common Eastman chemical sensitizing dyes.
    www.thelightfarm.com
    Dedicated to Handmade Silver Gelatin Paper, Film, and Dry Plates.

  7. #157
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    Denise;

    A Br/I emulsion with a percentage of the Iodide on the surface would work well with the Iodide salt of a Cyanine dye. This pretty much includes most of today's modern emulsions.

    PE



 

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