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  1. #21
    Alex Hawley's Avatar
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    Quote Originally Posted by Photo Engineer View Post
    You may be using up or absorbing some contaminant. IDK, but I have had that before in some situations where a photo active ingredient is present at a very low concentration and is used up.
    That's a good, plausible explanation Ron. Some sort of compound is formed during mixing then reacts with the paper emulsion. I've come to believe that its a quirk of amidol that has to be lived with.
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  2. #22
    David A. Goldfarb's Avatar
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    How often is the first print of a session a final version? If it's a test print anyway, a little staining usually isn't important.
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  3. #23
    Alex Hawley's Avatar
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    Right David. That applies to all developers IMO. Make sure the chemistry is all settled out, run two or three prints to make sure, or two or three blank pieces of paper.

    My point is that I've seen the pink stain sporadically with what's probably the best amidol that can be obtained. I wonder what it was like in years past when amidol was produced by more sources and in much larger quantities?

    Here's the kicker question: Did Weston have this problem? (no debate initiation intended ).
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  4. #24
    Photo Engineer's Avatar
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    Quote Originally Posted by David A. Goldfarb View Post
    How often is the first print of a session a final version? If it's a test print anyway, a little staining usually isn't important.
    Sometimes this small difference can make the evaluation difficult for the change needed for the next print. The curve shape can even change. I've seen that myself and I've ended up chasing an ever changing situation that led me down a garden path with a dead end. I've used up developers that had 'deltas' between every single print, and that is one reason why Liquidol was designed, to eliminate this very problem.

    I don't want to continue, as that would get me accused of 'advertizing', so this is merely an explanation of my answer and I'll leave it at that.

    PE

  5. #25

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    Quote Originally Posted by Ole View Post
    Your link is buggered - it should be http://michaelandpaula.com/mp/AzoFor...ID=10524&CID=5
    ...
    What's worse is that it doesn't make sense at all! There is absolutely no way that 98% Amidol can contain 39.18% Magnesium and 11.24% Calcium by weight.
    ...
    The table is misleading because amidol is mostly C, H, and N, which are not included. The levels still seem high. I would be interested in an MS analysis to identify organics and their levels.

  6. #26
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    Chemical analyses of this sort start by giving the theoretical % of C, H, O, N, S etc, and then the actual values present.

    Thus: Calc for C10H14N2O: C, 67.38; H, 7.92. Found C, 66.62; H, 7.66. And etc.... The error in ratios of C, H, N and O in this type of representation will tell you how much amidol there is and how much is organic and metallic junk. (this example is not Amidol, it is hypothetical taken from an off the shelf text)

    The analysis as given in the reference is not revealing in any way.

    PE

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