Collodion Emulsion - emphasis on EMULSION

Discussion in 'Alternative Processes' started by holmburgers, Apr 25, 2012.

  1. holmburgers

    holmburgers Member

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    I was recently recommended to read Collodion Emulsion and its Applications to Various Photographic and Photo-Mechanical Purposes with Special Reference to Trichromatic Process Work, by Henry Oscar Klein. (available here). Ask for that at your library 5 times fast!

    In short, this process is distinctly different from wet collodion and those collodion dry plates that used various humectants. This wikipedia blip will give you the best description of it -> here.

    The above book is fascinating. Basically, collodion emulsions can be sensitized to all regions of light and thus can be used for color photography. It uses aniline dyes to do this, much in the way that gelatin emulsions use dye sensitizers, but it appears that generally they're a different class of dyes (or are they?).

    I don't have much to say on it, other than to just mention it, bring it to someone's attention if they've never heard of it, and to solicit any information about it. Frankly, I wondered where had this been hiding my whole life! It seems like a process that's really under the radar and particularly so considering the color bit.

    Furthermore, it's claimed that the speed of these collodion emulsions, appropriately sensitized, can beat or match gelatin plates of the same era. This was how the majority of color separation work was done at the turn of the century I guess. Just imagine; the resolving power of collodion with full color sensitivity.

    To Dr. Albert, however, is due the credit of having first discovered the surprising sensitising power of a very concentrated solution of eosin silver in ammonia. Without his example others Would not so quickly have come upon the interesting fact that it is possible to prepare colour-sensitive collodion emulsion attaining the sensitiveness of gelatine emulsion. Dr. Albert has thereby opened a new road. (from here)
     
  2. dwross

    dwross Subscriber

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  3. holmburgers

    holmburgers Member

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    Awesome, thank you Denise. Klein refers to it endlessly in his book, glad to have access to it.

    I wonder if collodion emulsion could give a tin-type or ambrotype...
     
  4. kb3lms

    kb3lms Subscriber

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    Neat book, Denise. I've got to get hold of the oher book as well.

    Where does one get Cyanine? For red sensitizing, this always seems to be the problem.

    BTW, if you didn't know, in the wikipedia collodion preparation example, pyroxlin is cellulose nitrate. We all know what that can do.
     
  5. Mark Osterman

    Mark Osterman Member

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    The Many Flavors of Collodion

    Yes, beyond wet collodion there is moist preserved collodion, dry preserved collodion, unwashed collodion emulsion and washed collodion emulsion.

    The collodion emulsions are really interesting because they seem like they shouldn't work, given that they are in a binder that doesn't absorb water so easily when dry. Collodion chloride emulsions for printing out paper are the easiest printng process invented. Unlike gelatin emulsions, a beginner can make the emulsion and coat a perfect sheet of paper that looks like factory made on the very first try. And...the final product is more archival than any silver gelatin product. The way we identify collodion pop prints in conservation is that they are the ones that don't fade. ;-)

    Washed emulsions like those described in Klein's book are also amazing...but require more money to make. The mixed emulsion is poured though water and the "noodles" collected, dried and then mixed with more alcohol and ether. Those are the ones that were dye sensitized. The earliest dye sensitized plates used chlorphyl as the dye and were simply silver bromide wet plates...which were then washed individually. Yes, you can make dry plate tintypes with a washed silver bromide collodion emulsion.... but wet plate is faster and cheaper.

    We have a collodion chloride emulsion workshop in November for anyone who is interested.

    http://www.eastmanhouse.org/events/series/photo-workshops

    Or contact me with questions...Mark mosterman@geh.org
     
  6. holmburgers

    holmburgers Member

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    Mark, a pleasure to have your input here; nobody's better suited to highlight the finer points of collodion than you!

    Well then, how do they work? I always got the impression that if your wet-plate dried, you were up a creek. So what's different about collodion-emulsions? It seems that the silver-salt being inside the collodion would make these even worse, but obviously I'm missing something..

    Isn't it also true that collodion emulsions were used up until fairly recently for certain uses? I've seen a mordern, yellow Kodak box labeled 'Collodion' that appeared to be from the 60s/70s. Maybe for certain industrial process, photo-reproduction, or copy work?

    Sincere thanks,

    Chris
     
  7. Jerevan

    Jerevan Subscriber

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    Doesn't the mix of paper and collodion sound a bit... dangerous/flammable?

    I am intrigued by all this - never knew there were so many variations of the collodion. Now I need to win the lottery so I can go to the workshop in November. :smile: