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  1. #1
    Photo Engineer's Avatar
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    Making your own film

    Here is an update on film emulsion making and coating.

    I have made 5 attempts to make an entirely new type of emulsion which have failed utterly. This method was intended to duplicate the ammonia digest emulsion previously posted but without the ammonia. It didn't work. I have another type in the wings to work on but as of now, the SRAD (Single Run Ammonia Digest) posted below with some modifications is the best. Runs still peg it at about 40 ISO when ortho sensitized.

    As for coating it, I have observed better results at my leisure here than during a workshop. I have now isolated the problem. In the rush of giving the workshop, the film and plate coatings are used within 24 hours to fit it into the course. It turns out that this introduces micro reticulation into the coating as the hardening is not complete. It also allows for more frilling especially on glass plates.

    In addition, the contrast varies comparing ones done here and ones done in workshops. The latter are considerably lower than what I get here at my leisure. Well, in the haste of the workshop, the ammonia-silver 'digest' is given 3 days or more, but in class it is given, at best, 2 days. This lowers final contrast considerably.

    So, long and slow is the deal with the 'real formula' posted below to get optimum contrast and speed.

    Now, about coating. I think that the film will have to be coated at about 25% greater silver per unit area than I currently use. I'm working on that.

    In addition, it will probably be impossible to get useful coatings on 120 size film. Sheet film of 6x7 and up is possible with probably 11x20 being the largest practical size. The smaller sizes will be sharp enough, but grain will probably be bad. From 4x5 up, the grain and sharpness will be quite good.

    If one accepts a speed of about 12, then you will have fine grain and good sharpness in plates and films down to about 6x7.

    I am giving the plate coater a good workout and it seems to do well. If it works out, this plate coater will simplify all plate coatings. I'm currently working on a method to allow one blade to do all sizes of plates, but that may not be possible. Right now, I can do only 4x5 plates.

    I have tried to answer most of your questions in one post here.

    PE

  2. #2
    John Bartley's Avatar
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    Thank you for continuing with this posting about your emulsion experimenting Ron. I read all these threads. I don't understand most of it, but with each post a bit more sinks in and cures before it evaporates.

  3. #3
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    Kodak told me they would be in the film and chemical business for some time to come due to steady and strong demand as a digital input medium. Paper is the problem area.
    Everytime I find a film or paper that I like, they discontinue it. - Paul Strand - Aperture monograph on Strand

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    Ok Curt, I'll concentrate on paper, and when I kick off to a happier place, I'll gladly take all of the film formulas with me. Then, in another few years, you will have to come up with your own.

    Seriously, the poll earlier was divided about 50% AZO, 25% Enlarging papers and 25% films/plates. I'm trying to split my time accordingly.

    PE

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    Curt's Avatar
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    PE, if I have to come up with my own; I won't. I'm not so stupid as to think I can solve the problem of reinventing film.

    Seriously though I did write to Eastman Kodak Company and they told me that film and chemicals are in strong demand and they were out of the paper production part of business. Therefore in the near future it appears that paper is a problem area. Either someone will work to produce it or it will end. That's the evolution of civilization and it's heroic to hold the doors open and I applaud you for all of your work as I have read everything you have posted here with great interest.

    History has shown that even with the formulas or instructions for the making of something it doesn't mean that just anyone can do it. If I had a good emulsion formula even with a science degree would I have the equipment and conditions to make film?

    All of the materials are available to make a light bulb, how many people can make them at home? How many can make enough to sell on a consistent basis with a consistent quality?

    Then there is the reality that if I am busy making film and paper when do I do photography? If I were younger I might have a better outlook but the older I get the more realistic I become.

    I'm quite aware that the magic in the tray is the result of many many hard working individuals who get up and go to work all day long so many others can have an Art.
    Everytime I find a film or paper that I like, they discontinue it. - Paul Strand - Aperture monograph on Strand

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    Quote Originally Posted by Curt View Post
    Seriously though I did write to Eastman Kodak Company and they told me that film and chemicals are in strong demand and they were out of the paper production part of business. Therefore in the near future it appears that paper is a problem area.
    That's counter-intuitive to me. There are plenty of 1-hour places like Walmart and Ritz that seem to be making their money printing digital photos on real photo paper. I'd expect that paper (at least color paper) would be the last thing digital would kill off.

  7. #7
    Michel Hardy-Vallée's Avatar
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    Quote Originally Posted by 3Dfan View Post
    That's counter-intuitive to me. There are plenty of 1-hour places like Walmart and Ritz that seem to be making their money printing digital photos on real photo paper. I'd expect that paper (at least color paper) would be the last thing digital would kill off.
    Kodak still sells color paper, which the 1-hour labs gobble by the ton. It's their B&W papers that they have sacrified on the altar of commerce.
    Using film since before it was hip.


    "One of the most singular characters of the hyposulphites, is the property their solutions possess of dissolving muriate of silver and retaining it in considerable quantity in permanent solution" — Sir John Frederick William Herschel, "On the Hyposulphurous Acid and its Compounds." The Edinburgh Philosophical Journal, Vol. 1 (8 Jan. 1819): 8-29. p. 11

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  8. #8

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    Quote Originally Posted by Photo Engineer View Post
    ...I have now isolated the problem. In the rush of giving the workshop, the film and plate coatings are used within 24 hours to fit it into the course. It turns out that this introduces micro reticulation into the coating as the hardening is not complete. It also allows for more frilling especially on glass plates.

    In addition, the contrast varies comparing ones done here and ones done in workshops. The latter are considerably lower than what I get here at my leisure. Well, in the haste of the workshop, the ammonia-silver 'digest' is given 3 days or more, but in class it is given, at best, 2 days. This lowers final contrast considerably...
    It's probably time for your workshops to adopt the approach that television cooking shows use. While demonstrating the entire process, also bring some pre-aged digests and coatings. Then participants can see what optimum results will look like and also take home their own work to finish after appropriate aging.

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    Curt's Avatar
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    It's probably time for your workshops to adopt the approach that television cooking shows use. While demonstrating the entire process, also bring some pre-aged digests and coatings. Then participants can see what optimum results will look like and also take home their own work to finish after appropriate aging.

    Now that's the best solution I've heard so far. Thanks Sal!
    Everytime I find a film or paper that I like, they discontinue it. - Paul Strand - Aperture monograph on Strand

  10. #10
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    Quote Originally Posted by Sal Santamaura View Post
    It's probably time for your workshops to adopt the approach that television cooking shows use. While demonstrating the entire process, also bring some pre-aged digests and coatings. Then participants can see what optimum results will look like and also take home their own work to finish after appropriate aging.

    Yep, thanks.

    I'd probably try it, but they don't travel well. They must be refrigerated or they spoil. Emulsions will change rapidly at room temperature and this is one of the major problems. They are like food items on the shelf at a store. Imagine taking a trip across country by train or plane and carrying a steak with you.

    Now, I know that steaks can be packed in dry ice, but before you suggest this, I have to tell you that a raw emulsion cannot be frozen. That will ruin it too.

    I will try to arrive early to Montana and make one in advance.

    That is about all I can do.

    PE

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