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Thread: Plus X anomaly?

  1. #1

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    Plus X anomaly?

    I processed a single roll of 35mm Plus X in D-76 1:1, water stop, and TF-4 fix. Half the roll was exposed at 80 and the other half at 125 because of lighting conditions.

    The frames exposed at 80 have a distinct brown cast/stain while the frames exposed at 125 are the normal blue-gray appearance and what I normally expect.

    I have never noticed this before.

    Thanks!

    -F.

  2. #2

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    Are the frames grouped into to sets by exposure? (eg, first half at 80, second half at 125), or did you go back and forth between lighting situations?

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    First half at 80, second half at 125. I think I read somewhere that TF-4 fixer is prone to brownish negs, but I can't find the reference.

    -F.

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    Matthew Gorringe's Avatar
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    Very strange Fred,
    My Plus-X negs are quite brown but I had assumed it was the Pyrocat-HD that was making them so. I've only ever processed them in Pyrocat-HD and like you I use a water stop and TF-4 fix. I expose it at ISO64 and place imortant shadows on Zone 3.

    It's really interesting that the extra exposure seems to be what's making them go brown. Does the base fog look blueish or brownish?
    Matt Gorringe

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    The base fog on unexposed film is clear and slightly bluish.

    -F.

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    Matthew Gorringe's Avatar
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    In paper processing image tone is said to depend on the size of the grains in the emulsion with smaller grain being warmer and larger grain being colder.

    Could it be that Plus-X has enough of a difference in grain sizes in the one emulsion that less exposure will favour the larger, more light sensitive and bluer grains and more exposure activates the smaller, less sensitive and browner grains?
    Matt Gorringe

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    DWThomas's Avatar
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    I guess I've not done a series where I would have had the opportunity to notice that. Since the negs shot at lower EI were brown, I wonder if it's just a denser build-up of brownish silver particles overcoming the blues/grays of the base and emulsion? Are the more heavily exposed negatives visually more dense?

    DaveT

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    DaveT, yes, the negs exposed at 80 are visually denser than the negs at 125, about 2/3 stop, as would be expected. I think you are on to something as I checked a couple of other rolls shot at 80 and they have the brownish cast. It is not too noticeable unless you have a mixed roll, then they are very noticeable. BTW, I use d76 original formula, hand mixed. Perhaps the brownish cast is an indicator that the film is being overexposed by some amount.

    -F.
    Last edited by Fred Aspen; 03-28-2009 at 08:43 AM. Click to view previous post history.

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    Jim Noel's Avatar
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    Pyrocat stains proportionally to the amount of reduced silver. I am wondering if the extra exposure is putting enough extra light on the film to cause the staining effect of the developer to be more apparent. If so wouldn't this indicate overexposure?
    [FONT=Comic Sans MS]Films NOT Dead - Just getting fixed![/FONT]

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    Quote Originally Posted by Jim Noel View Post
    Pyrocat stains proportionally to the amount of reduced silver. I am wondering if the extra exposure is putting enough extra light on the film to cause the staining effect of the developer to be more apparent. If so wouldn't this indicate overexposure?
    That is exactly what I was thinking as well. But 2/3 of a stop doesn't seem like much overexposure unless PX is that sensitive. I have never noticed that before.

    BTW, the camera is a recently CLA Leica R4S in manual mode.

    -F.

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