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  1. #61
    Diapositivo's Avatar
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    I don't understand a lot of this from the theoretical point of view, but the lesson I get from this is:

    If 0.01 g/sqm residue is "commercially" sufficient, than Greg tests give peace of mind to all those who follow this procedure, provided the water is not significantly different;

    To take into account difference in water quality, add another rinse. No problem.

    Because 0.01 g/sqm might not be enough for archival quality, add yet another rinse and you'll have archival quality anyway, so that your grand-grand-nephew can make observations about your pictures, after having already inherited from your heirs that is.

    So any published method for washing is good for most purposes (thanks Greg) and if you really want to be sure to reach archival quality just add a rinse or a couple of rinses (thanks Erik) for your descendants' enjoyment.

    Fabrizio
    Water is cheap.

  2. #62
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    Quote Originally Posted by ic-racer View Post
    Jeff, page 27 of the 1970s Kodak Darkroom Dataguide has the HT-2 formula and the color patches. You never got one of those Dataguides in any boxes of equipment??

    I think I could scan/print it out to be pretty close.
    Page 29 of the 1980 (silver cover) Darkroom Dataguide has (almost) the same formula and colour patches.

    The only difference in the formula from the 1970 version is that the 1970 guide included both Avoirdupois and metric measures.

    Unfortunately, the 1980 Dataguide doesn't have the neat paper samples that the 1970 Dataguide does.
    Matt

    “Photography is a complex and fluid medium, and its many factors are not applied in simple sequence. Rather, the process may be likened to the art of the juggler in keeping many balls in the air at one time!”

    Ansel Adams, from the introduction to The Negative - The New Ansel Adams Photography Series / Book 2

  3. #63
    Marco B's Avatar
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    Quote Originally Posted by Greg Davis View Post
    Thank you, Pentaxuser and Ron. The whole purpose of the project was as a teaching aid in class, as well as to stop the arguing here since nobody else was willing to actually put these methods to the test instead of arguing which was best simply because they used that particular method.
    Thanks so much for the effort! As you say, nothing beats some real results of a more or less controlled test instead of just speculation...

    Quote Originally Posted by Diapositivo View Post
    The results should stick somewhere before time buries this thread under the new ones.
    Quote Originally Posted by Greg Davis View Post
    We could ask the moderators to make this a sticky.
    Yes, you should. Or otherwise, create an "Article" in the "Articles" section to give it a "permanent" nature. Well worth it, and it doesn't have to be anything fancy, just include the stuff and posts as posted here in the thread.
    My website

    "The nineteenth century began by believing that what was reasonable was true, and it wound up by believing that what it saw a photograph of, was true." - William M. Ivins Jr.

    "I don't know, maybe we should disinvent color, and we could just shoot Black & White." - David Burnett in 1978

    "Analog is chemistry + physics, digital is physics + math, which ones did you like most?"

  4. #64
    Photo Engineer's Avatar
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    Haist, and I believe Mees or Mees and James give archival and commercial values for retained hypo in photo products. Other documents and texts give these values as well. These values are also explained in the PDF files above which refer us to the ANSI standards.

    PE

  5. #65

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    This started as such a great post. Too bad it turned negative so soon.
    If you don't like what you read offer some nice ideas for improvement that you can back up with some real test data (your own or published by others). Not just some back of the napkin assumptions and calculations. I hate to waste my time with petty arguments.
    Last edited by brianmquinn; 11-26-2010 at 12:19 AM. Click to view previous post history.

  6. #66
    Jeff Bannow's Avatar
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    Quote Originally Posted by ic-racer View Post
    Jeff, page 27 of the 1970s Kodak Darkroom Dataguide has the HT-2 formula and the color patches. You never got one of those Dataguides in any boxes of equipment??

    I think I could scan/print it out to be pretty close.
    Thanks - looks like I need to find a copy of the Dataguide now! I looked and I don't have a copy. Is there a preferred version out there?
    - Jeff (& sometimes Eva, too) - http://www.jeffbannow.com

  7. #67
    Jeff Bannow's Avatar
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    Quote Originally Posted by Greg Davis View Post
    Here is the documentation that came with the Kodak Hypo Estimator Pub. No. J-11.
    And for those who want a combined PDF to archive, here you go.

    Hope you don't mind Greg, and thanks for scanning these pages for all of us!

    Also, you can find a scan of the hypo estimator card here: HT-2
    Attached Files
    - Jeff (& sometimes Eva, too) - http://www.jeffbannow.com

  8. #68
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    thank you

    Thank you, Greg.

    Taking the time to post your results is very much appreciated.

  9. #69
    Lee L's Avatar
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    Here is another study of the Ilford wash method:

    http://www.largeformatphotography.in...or/ilfwash.pdf

    Lee

  10. #70
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    Lee, Guys;

    Calculations as shown in such articles miss one point. They use simple arithmetic to calculate residuals, but in actuality the process of washing is dynamic and requires calculus. I have posted Mason's equation at least two if not 3 times here before that shows the actual relationships obtaining in washing. The final result is a function of dC/dT or the change in concentration vs time. This is what confuses the issue. Particularly since there are influences on this by the amount of residuals leaving the film and the amount of residuals trying to re-enter the film (or paper as the case may be).

    This is why a practical result is always so much better than the math model.

    PE



 

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