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Thread: Glass plates

  1. #41

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    I see. Yes contact emulsion is simpler as I said before, but the difference is like making a cup of tea with shorter steeping time with different amount of milk and sugar. You still need to boil water to the correct temperature for the leaf, and must have appropriate teapot and strainer. So the major requirement remains the same.

    Contact printing emulsions don't have to be fast, so one requirement is already out of the equation. The issue is to get good contrast and low fog. In my experience, the emulsion part is easy, as long as you have good inert photographic gelatin. The difficult part is to coat it on the paper. Almost all paper stocks I tried fog silver chloride emulsion when they contact. So you have to size the paper with well hardened photographic gelatin and coat the emulsion on top of it (which is generally a good thing for improving image quality as well). Then avoid the edges of the paper and coat in areas like an inch from thee dges.

    Alternatively, you can make a very slow bromide emulsion. It requires a bit more steps but the emulsion is a lot more robust against fogging.

    You'll need a reacting vessel (glass, glazed earthware or titanium - no other metals, though high corrosion resistant stainless steel is also good) at temperature of 50 degrees centigrade in water jacket. This vessel has to be stirred very rapidly for an hour or so. A good mechanical stirring is a plus, but you can do it with hand for proof of concept. You also need some deionized water, photographic gelatin, silver nitrate, sodium chloride, potassium bromide, potassium iodide, sodium thiosulfate, benzotriazole, and a refrigerator (in darkroom) as a bare minimum requirement.

    Anyone still willing to try? You should email me, because the whole process is more than what I'm wiling to punch into this tiny text box.

  2. #42
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    Quote Originally Posted by Ryuji
    [...]
    Anyone still willing to try? You should email me, because the whole process is more than what I'm wiling to punch into this tiny text box.

    Ryuji,

    I'm sure I'm not the only one whose eager to find out what's involved, just out of curiosity if not anything else. Why not write an article for APUG?

    I'm clueless about the mechanics of submitting an article. I'll paste some links to what might be relevant threads below, but they seem to indicate that there's a "submit article" menu choice, and I can't find it. Sean@apug.org would know for sure, though. Also, numerous folks have already gotten articles submitted -- so I'm assuming they'd know as well.

    Article submission threads... possibly...
    http://www.apug.org/forums/showthrea...light=articles
    http://www.apug.org/forums/showthrea...light=articles

    -KwM-

  3. #43

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    Quote Originally Posted by jdef
    I don't have room for a refrigerator in my darkroom, so I'll have to wait until I move into more spacious facilities. I have a mag stirrer, but not a hotplate stirrer, which might be more useful. As long as there are intelligent, creative people working on a problem, I'm optomistic that one day it will be simplified to the point that even I can get decent results. Thank you.
    I understand. I started my emulsion project a couple of years ago. The biggest problem was to find a space where I can do this project. Renting 200 sqf with no window but with ventilation, running water and affordable rent for me was close to impossible in Boston. Then I spent nights at library xeroxing relevant papers, and weekends in my darkroom making test batches and printing step wedges. I've paid for the photocopier cards and library fines for the price of a pound of silver nitrate, analytical reagent grade.

    My emulsion formulae are simple, especially if you consider the performance. Experts at Fuji or Eastman would laugh, I am very sure, but I don't want compromise in image quality so my formulae evolved to overcome some limitations of my limited setup. The reaction vessels used in those top end plants are equipped with multiple mixers, premixing chamber and premixer, multiple calibrated nozzles, and all sorts of measurement probes in the solution with everything under feedback control and computer profiling. In my setup, I have a hotplate magnetic stirrer with a glazed ceramic jar (with a lighttight lid, very important when I want to make a cup of tea in a very long emulsion making process), and jetting solutions through pipettes or syringes with no measurement and no feedback. The price is that the photographic performance depends on the "art" of mixing, not just dissolving how much of what goes in which solution. It's kinda like making hollandaise sauce from raw ingredients. You need certain skill to do it well.

    So, one advice from me for those who found old emulsion books in libraries - using more chemicals is the cheapest part of emulsion making. If more work, more chemicals, more steps can really solve the problem, it is a real bargain. Don't be discouraged by the number of agents and steps required.

  4. #44

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    Quote Originally Posted by kwmullet

    I'm sure I'm not the only one whose eager to find out what's involved, just out of curiosity if not anything else. Why not write an article for APUG?
    Well, I could publish it on my website as well. I'm thinking about what is the best way to share this info with others, but I am also worried about the "technical support" load. I disclosed several of my developer formulae like DS-1, 2, 8, 10, 12, 14, 15 and maybe a few others. I highly appreciate feedbacks (particularly because people like DS-10, 12 and 14 so much), but I also get questions and requests for suggestions for fixing problems of someone else's formulae that I don't know about... I've made my developers and tested myself for some time before disclosing the formulae, and I know they work out of the box, with no fog, etc, etc. BUT emulsions, I test them all and some of them remain in my formula book, but I still have vivid memory of failure after failure after failure and I can easily imagine many of you repeat some of that experience, though you'll have to know common problem areas to avoid many of them. (And some of the problems I had was not even mentioned in any literature I consulted.)

    As a long term project, I'm making a booklet of silver gelatin photography. Part 1 is emulsion, Part 2 is processing chemistry. So people can continue to make silver based b&w photographs without commercial supplies. I think this is a very nice idea. I probably sell 5 copies at APUG and 10 copies in the rest of the world. I am still skeptical how many people are willing to pay to know these, much less willing to try after knowing the investment in time and money.

  5. #45

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    I've looked into making my own glass plates. Making the emulsions is a fine science, and requires a rather large investment in scientific apparatus to properly mix the emulsion (specifically to heat, wash, and strain it).

    If you're really interested, email me and I will send you copies of the documents I have.

    I found it to be financially impossible for anyone but a retired millionaire.

    On the other hand, if you got it working, I'd buy some plates.
    -Jason Antman

    "There is nothing worse than a sharp photograph of a fuzzy concept." - A. A.

  6. #46

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    Quote Originally Posted by jantman
    I've looked into making my own glass plates. Making the emulsions is a fine science, and requires a rather large investment in scientific apparatus to properly mix the emulsion (specifically to heat, wash, and strain it).

    If you're really interested, email me and I will send you copies of the documents I have.

    I found it to be financially impossible for anyone but a retired millionaire.

    On the other hand, if you got it working, I'd buy some plates.
    My low tech apparatus costed me less than a couple of towing fees and parking ticket in my city. I spent a lot more money and time to figure out what works and what doesn't. If I had someone advising me what to do from the beginning, the course would be a lot easier.

    But frankly, I got absolutely the biggest excitement when I saw images developing from my emulsion. It was even bigger excitement than my very first darkroom experience. Actually I got visible image from my very first emulsion. It was just that I didn't want to make any serious image with that crappy image quality.

    Most of the decent old formulae require emulsion be chill set to stiff jelley, shread it into noodles and wash the noodle in cold water for several hours with a few changes of water. This is a lot of work and requires a lot of gelatin in the emulsion, leading to thicker coating and less sharp image. Well, this is the simplest way for beginners but those who are chemically concious will find that this process can be sped up with a couple of extra chemicals (or if you could buy a certain kind of modified gelatin). It can be done in mere 20-30 minutes that way, with a lot less water. But of course this would make initial investment greater, though these chemicals are cheap.

    I'm a poor unemployed but I can do it. But I don't have time, money or motivation to commercialize it. If you have a nice coating machine and good supplies of glass, you can commercialize my emulsions and pay me the licensing fee in plates. Indeed, I heard you can buy plates from Russia if you just want to use them.

    PS. a couple of people wrote me asking for more details. Will follow up soon.

  7. #47
    Ole
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    Well, I've just received 3 packs of Russian plates - Slavich PFN-01T. From what I can read from the pack they are Isooptochromatic, with a speed of 160 GOST.

    No, I'm not going to shoot test targets with them! I'll load two in holders for my old Voigtländer Bergheil 9x12cm, and another two in Linhof Universal 9x12 plate/film holders. Then I'll go out and take some pictures. Depending on results I'll then decide how best to use the rest, and whether to buy more.
    -- Ole Tjugen, Luddite Elitist
    Norway

  8. #48
    Ole
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    Forgot to mention - Retrophotographic still have a few packs of plates available if anyone else wants to try!
    -- Ole Tjugen, Luddite Elitist
    Norway

  9. #49
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    Quote Originally Posted by Ole
    Forgot to mention - Retrophotographic still have a few packs of plates available if anyone else wants to try!
    Want to? You bet; my 1927 Ideal probably hasn't had a glass plate in it in at least fifty years.

    Able? Not likely -- aren't those something like $8 US per plate, plus shipping from UK to US? And then I'd have to find a way to develop glass plates without a real darkroom (hint -- I'm not developing in trays in my changing bag).
    Photography has always fascinated me -- as a child, simply for the magic of capturing an image onto glossy paper with a little box, but as an adult because of the unique juxtaposition of science and art -- the physics of optics, the mechanics of the camera, the chemistry of film and developer, alongside the art in seeing, composing, exposing, processing and printing.

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