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  1. #311
    Photo Engineer's Avatar
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    I agree with Curt.

    I've said all I wish to say and will no longer post in this thread.

    Rest in peace.

    PE

  2. #312

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    Quote Originally Posted by Photo Engineer View Post
    I agree with Curt.

    I've said all I wish to say and will no longer post in this thread.

    Rest in peace.

    PE
    To bad, because there is still the issue of the physical chemistry of diffusion of ions that needs to be cleared up.

  3. #313

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    Quote Originally Posted by Sirius Glass View Post
    Stop bath should not be used with some developers. Pyro needs an alkaline archival fixer such as TF4 or TF5. Example, Rollo Pyro developer should not have stop bath used because it needs a fixer like TF-4 or TF-5 after a water wash.
    Sandy King has said that stop baths are not detrimental to pyro developer use. I've tested water bath vs. stop bath with PMK and found there is minimal differences in film densities between the two. (If you're curious, the stop bathed neg was lower in density in the denser steps than the water bathed neg by about 0.02 OD - probably simple variance in the method of the test, or perhaps the stop bath stopped the development sooner than the running water bath did.)

    What's your proof for your statement?
    Last edited by Kirk Keyes; 07-23-2010 at 06:37 PM. Click to view previous post history.
    Kirk

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

  4. #314

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    Discussing things is about (or should be at least) finding out how they really are.
    Referring to an authority in the field, to their explanations of how things are, is a good thing.
    But simply bowing to authority isn't very productive, is it?

  5. #315

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    Again, we learn by knowing how things are, delving into how things work.
    Not by discussing personalities.

  6. #316

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    Ian-Yes, I think you are correct about the about the origin of plain water rather than acid stops for negatives.

    Q. G.-
    In this case, I did not have to "choose" a side...
    I already possesed one of my own!

    alanrockwood-I agree, I hope PE only meant he would stop beating that poor horse,
    not drop out of the the more thought provoking P-Chem discussion.

    Quote Originally Posted by Thomas Bertilsson View Post
    Strange story but true...
    On the first day after moving to Japan,
    I had the strange experience of visiting the funeral of a young man who was said to have
    died sleeping under a "kotatsu"... (a heated table with a blanket covering)...
    A man, crying, came up to the body and started pounding on it screaming "wake up you stupid son of a bitch!"

    I couldn't belive my eyes.

  7. #317

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    Quote Originally Posted by Sirius Glass View Post
    It was the tone from Mount Olympus that I was taking a shot at.

    Steve
    I offered more than a declaration from Mt. Olympus. I offered actual test results.

    It's a simple test to do. Take two sheets, expose them identically and then process them together in your pyro-based developer of choice. Then, when development is done, place one into a running water bath and the other into stop bath. Then fix them side-by-side and finish processing thme together. Take a color densitometer and measure the density in RGB and VIS density settings. Compare the results.

    That's what I did. And there's was no significant difference from my measurements.

    What evidence did your experts give?
    Kirk

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

  8. #318

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    Quote Originally Posted by Sirius Glass View Post
    The word of the master, Per Volquartz. I have never found him to be wrong and I do not waste my time testing every possibility in hopes I can raise my ego by finding a mistake.
    I've spent a week with Per with him on his Free Oregon Coast Workshop. He's a nice guy and a very talented photographer.

    But maybe you should do some testing for yourself sometimes. You may discover that some popular notions are not true...

    Gordon Hutching, in his Book of Pyro recommended saving spent PMK developer to use as an "afterbath" for soaking your developed and fixed PMK films in to increase the strength of the pyro stain on the negatives. I first used PMK in the early 90s, and I followed his suggestion. To me, it initially seemed counter intuitive, but I did it as it was in the Book, and so I did it religiously.

    After some time, that counter intuitive feeling got to me and I did some testing and I found that the afterbath merely added an overall stain to the image. The afterbath increased the yellow color of the neg and increased the printing exposure time needed. It was just like cranking in some yellow filtration on my color head - and did not add to the quality of the pyro neg.

    By the way, I'm sure you've noticed that the afterbath recommendation is not made anymore. I guess others came to the same conclusion that I did.

    Anyway, I questioned the recommendation of a Master. And I learned something by doing some test to find the answer myself. And yes, I stopped following the suggestion of a Master.
    Last edited by Kirk Keyes; 07-24-2010 at 01:44 AM. Click to view previous post history.
    Kirk

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

  9. #319
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    Quote Originally Posted by Kirk Keyes View Post
    Gordon Hutching, in his Book of Pyro recommended saving spent PMK developer to use as an "afterbath" for soaking your developed and fixed PMK films in to increase the strength of the pyro stain on the negatives. I first used PMK in the early 90s, and I followed his suggestion. To me, it initially seemed counter intuitive, but I did it as it was in the Book, and so I did it religiously.
    He later retracted that, all that happens is an overall base stain is added, it's not a benefit and if patchy highly detrimental. So you did the right thing (in your next paragraph)

    Ian

  10. #320

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    Ian - I think a lot of the recent popularity of the notion of using water baths is a combination of the "Book of Pyro" suggesting the use of the alkaline afterbath (used PMK developer) and Anchell and Troop's "Film Developer Cookbook" recommendation of an "all alkaline" film development process. Bill Troop suggested the use of waterbaths instead of stop bath with his alkaline fixers.

    In a phone call I had with Bill Troop, he told me that a buffered stop bath was the ideal way to use a stop bath. By adding sodium acetate to an acetic acid solution, a buffered stop can be made. It has a much greater capacity than regular stop as it has a greater acidity, yet it has a higher pH than a simple acetic acid stop. The pH can be about 4.5 to 5 and stop film much faster than regular stop baths. I asked him why he did not promote that idea more in his book, and I believe he replied that there's only so much room in a book, and that he thought the average darkroom worker would not want to go to the extra expense of making buffered stop bath, given how inexpensive regular stop bath is.

    So I followed the advice of a "Master" - I now use buffered stop bath by adding sodium acetate to water and then adding acetic acid to the solution until the pH is about 4.5 to 5.
    Kirk

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



 

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