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  1. #21

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    Quote Originally Posted by Ryuji View Post
    I also thought about making a paste. Like toothpaste. You decide like take 10cm per liter of water to make working developer.
    I like the idea of a paste. Have you considered packaging it in a wide shallow jar like a facial cream? The user would measure level spoonfuls of it. The jar could come with two or three sizes of cheap plastic spoons. But then some cream would be on the bottoms of the spoons, adding too much concentrate. Hmm, there must be some way to use a paste...

    Mark Overton

  2. #22
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    I look forward to hearing about the results.

    What I vaguely recall, from mixing my own monobath developers, is that there is some magic to the order in which things are brought into solution. I.e. one doesn't add all the phenidone at once. But I'm sure you'll work it out.

    Some time ago I was thinking that some monobath paste / goop woudl be really handy. Seems like it wouldn't be too hard to make a version of the type 55 stuff and a spreader that'd be good for very rapid development in the field.
    "Only dead fish follow the stream"

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  3. #23

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    Got a couple of tests done.

    Standard usage: take one tablespoon (15ml) of the mixed powder from the jar while stirring and dissolve in 870milliliter of water to make working solution. That is 20g/L. (The actual density of the powder mix is 1.18, so one tablespoon will be 17.4g assuming tablespoon is exactly half fluid ounce by volume.) If you are developing one 35mm film, that's one teaspoon of powder in 290ml of water. You can minimize the wastage by using a cheap digital balance. If you are doing push processing, 30g/L works better. If you are developing Acros or TMX, 15g/L gives more reasonable development time. The powder dissolved while I was loading the film.

    The powder mix is slightly yellowish. This is because of the developer stabilizing agent. Dimezone S is the orange granules. Several portions I took from the jar had exact same pH, plus/minus 0.05. Metering by measuring spoons has been pretty consistent, as well.

    Attached are the closeup of the powder mix (closeup, intentionally decreased exposure and boosted contrast to show the texture), another with Macbeth chart for color and reflectance reference. I just took the powder from the jar like usual, it did not come straight out of a mixer, but looks just like that. Then two sample images, exposed on Plus-X from 1990s exposed at EI 125 and developed in this soup, 5g in 250ml water, developed in stainless tank for 5.5 min at 22C. The film was exposed with a Russian toy camera, with a fixed focus lens, so the image isn't really Mamiya-sharp. But you get the tonality and feel. The developed negative scanned very well - fine grain, moderate accutance boost, lots of shadow details, and good highlight contrast.
    Attached Thumbnails Attached Thumbnails 20120110-IMG_3396_webSG.jpg   20120108-IMG_3236_webSG.jpg   20120110-IMG_3395_webSG.jpg   20120108-scan0001_webSG.jpg   20120108-scan0009_webSG.jpg  

    20120108-IMG_3233_webSG.jpg  
    Last edited by Ryuji; 01-10-2012 at 02:56 AM. Click to view previous post history.

  4. #24

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    Umm, so, Can I Test It?

  5. #25

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    Maybe I'll give out a limited number of samples, but for that, I'll have to think about how to package and ship...

  6. #26

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    Please count me in as first in line . PM me when you're ready I eagerly await.

  7. #27

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    A 35mm film canister holds about 30ml or 35g of this powder mix. One half of a film canister full of this stuff dissolved in 1 quart of water makes standard developer working solution.

  8. #28

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    Quote Originally Posted by Ryuji View Post
    Maybe I'll give out a limited number of samples, but for that, I'll have to think about how to package and ship...
    In my previous job, our products were subjected to "four corners testing": low/high temperature and low/high humidity. For a developer, the worst corner is probably hot-and-humid, and the south-east USA provides plenty of both.

    So it would be interesting to test this in an area like Florida. A good test would be to have the tester keep the jar in the garage (no A/C), and open/close the jar once a week. If the powder keeps much of its activity after a year of that, it's solid!

    Mark Overton

  9. #29

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    What's under the pH meter - a battery charger for it?

    (Sorry, you know my interest in lab gear!)
    Kirk

    For up from the ashes, up from the ashes, grow the roses of success!

  10. #30

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    Kirk,

    That meter can measure pH, oxidation/reduction potential and temperature. The meter runs on the built-in rechargeable battery, and is waterproof.

    The base unit is an induction based charger that sends the electric power to the handset without any exposed contact.

    It's not so much of an issue now, but when I had a much bigger lab space, I had an emulsion making station at one corner, processing station at another corner, and chemical preparation station (which also doubles as analytical bench) with its own sink in the middle. I had two pH meter setups back then, but a unit like this made my life a lot easier.

    This pH meter can recognize buffer automatically, and it also recognizes and calibrates at 9.18 if user chooses to do so. This is particularly useful for critical film developer work.

    BTW the values shown are the electrode hodling water and not the actual developer pH.

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