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Thread: Unexplicable exposure problem with paper negatives

  1. #11
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    Re: Unexplicable exposure problem with paper negatives

    Hi Tony

    Have you taken a sheet of paper or scrap ( it doesn't matter the size ) and put it in the developer with the lights on.

    John
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  2. #12

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    Re: Unexplicable exposure problem with paper negatives

    Quote Originally Posted by Jac@stafford.net View Post
    No disrespect intended. First remove all questionable variables. That means one batch lot of non-expired media (paper in this case), certifiably fresh chemistry, one light meter, one lens in same shutter, same time/temp processing.
    Long response sorry but!!!
    Generally I’d agree with your comments, BUT this time I’m trying to understand why things have changed.
    Initially I wondered if I’d not removed the dark slide – possibly on one image, but surely not on four.
    Then there was the question of malfunctioning of lens/shutter. By using variations of lens and shutters if some worked and the other did not then I had a starting point.
    Next I wondered about something happening when I inserted the DDS and/or removed a dark slide before taking the image. So I removed the lens from the camera, inserted a DDS and removed a dark slide. Nothing untoward occurred.
    I also wondered about the age of my developer [Ilford PQ Universal] concentrate. I contacted Ilford/Harman and got the reply: - “. the reddish brown colour indicates the developer is becoming oxidised. Whether you wish to continue using it is of course up to you, if you're happy with the results, then there will be no other issues using. Our guidance of 6 months is just an approximation.”
    To remove that element I ordered new developer that arrived a few days ago, but using it I got the same result of not ‘image’.
    So, one element left is the paper. It is out of date, of unknown origin in terms of storage etc. One possibility is that I’m inverting the paper in the DDS but my understanding is the RC curls/curves to the non-emulsion side FB curls/curves to the emulsion side, or that some of the paper in the 100 box was/is faulty.
    Two tests I intend to do.
    1] mark the four corners of the non-emulsion side of the 8x10 sheet and ensure that the paper is inserted emulsion side outwards.
    2] use paper from a 5x7 box of Multigrade paper.


    [QUOTE=jnantz;1503148]taken a sheet of paper or scrap and put it in the developer with the lights on. /QUOTE]

    I dropped a sheet of paper in daylight and later processed it through the developer and fixer. Result a black image so the chemicals worked and the paper is sensitive to light.
    Or did you mean as a way of determining the emulsion side - emulsion side darkens in daylight

    regards
    Tony
    Last edited by tonyowen; 8-Jun-2019 at 02:38. Reason: expanding reply

  3. #13
    Pastafarian supremo Rick A's Avatar
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    Re: Unexplicable exposure problem with paper negatives

    Are you loading your film holders in total darkness? Are you certain the emulsion side faces outward in the holder? If you are loading under a proper safelight, the emulsion side is shiny and will reflect light when held at an angle to the light. I think you possibly are loading the paper backwards into your film holders. I've used everything from fresh new paper to very old age fogged garbage, the only way you won't get an image is if loaded backwards or completely dead developer, or shutter doesn't fire and no exposure. Even underexposed should render a feint image. Try developing in a tray so you can watch the image appear. If you are using very dilute developer you may need more time for image to appear than you are giving in the processor.
    Rick Allen

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    Re: Unexplicable exposure problem with paper negatives

    Quote Originally Posted by tonyowen View Post
    Generally I’d agree with your comments, BUT this time I’m trying to understand why things have changed.
    Tony, try to keep your "investigation" under scientific method light.

    Use the DSLR photometer and just expose x20 the reading for ISO 100, take a paper and expose, you can extract fractions of the holder's slide to have several exposure levels in a single paper sheet, develop it inmediately in a tray under safe light.

    You have to find the problem with a few tests, this is straight, very easy find, just start from zero and be methodic...

  5. #15

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    Re: Unexplicable exposure problem with paper negatives

    Quote Originally Posted by Rick A View Post
    Are you loading your film holders in total darkness? Are you certain the emulsion side faces outward in the holder? If you are loading under a proper safelight, the emulsion side is shiny and will reflect light when held at an angle to the light. I think you possibly are loading the paper backwards into your film holders.
    Quote Originally Posted by Pere Casals View Post
    just start from zero and be methodic...
    Rick and Pere - thanks for input.
    I think I know what the problem is and I've worked out a scientific way [ie repeatable] to overcome it.

    Essentially some of the cut papers are being inserted with the emulsion to the INSIDE not OUTSIDE. This is from analysis of images since the time that resulting exposure paper negs became unpredictable. Also I've reason to suspect that some of the contents in the box of paper is mixed ie not what it says on the box.

    Wrong way round images are from paper correctly placed in DDS. Right way round images are from paper wrongly placed in DDS. These latter show up with very long exposures whereas for shorter exposures a partial image can sometimes be discerned, but most times nothing

    Initial solution
    1] mark what I assume to be the non-emulsion side of the 8x10 sheet on each corner.
    2] cut into two 100mmx254mm strips
    3] mark a line mid way [127mm] across the width or the strip on the same side as the corner marks.
    4] cut both strips to yield two 100mmx125mm pieces.
    5] expose the 4mm wide remainder marked with the 'mid way line' to daylight.
    6] whatever side of the strip darkens is the emulsion side.
    7] If necessary reverse the 100mmx125mm sections the DDS.

    Regards
    Tony
    Last edited by tonyowen; 8-Jun-2019 at 07:04. Reason: correcting typo

  6. #16
    Pastafarian supremo Rick A's Avatar
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    Re: Unexplicable exposure problem with paper negatives

    I gather from your response that you are not loading paper under a safelight, or you would be able to tell which side is which when loading, or you are using a safelight but not paying attention. There is also the possibility, if you are using old paper sourced from a private sale, that some of the paper is fixed out for alternate printing methods(or you are fixing first during processing).
    Rick Allen

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    Re: Unexplicable exposure problem with paper negatives

    Quote Originally Posted by Rick A View Post
    I gather from your response that you are not loading paper under a safelight, or you would be able to tell which side is which when loading, ...
    Pearl surface RC paper looks very similar on both sides. It can be difficult to tell which side is the emulsion side. This would be complicated if someone mixed up the paper in the box, i.e., some emulsion-side-up, some emulsion-side-down. There is a way to tell, but the OP will have to look very carefully. Definitely, a safelight is in order when loading.

    Best,

    Doremus

  8. #18

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    Re: Unexplicable exposure problem with paper negatives

    Quote Originally Posted by Doremus Scudder View Post
    Pearl surface RC paper looks very similar on both sides. It can be difficult to tell which side is the emulsion side. This would be complicated if someone mixed up the paper in the box, i.e., some emulsion-side-up, some emulsion-side-down. There is a way to tell, but the OP will have to look very carefully. Definitely, a safelight is in order when loading.

    Best,

    Doremus
    Paper and film always curl towards the emulsion side.

    Licking your finger and lightly touching a very small part of the material will also let you determine which side is which.

  9. #19

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    Re: Unexplicable exposure problem with paper negatives

    Yes, paper tends to curl with the emulsion inward. However, an exception is RA4 paper when it's cut recently from a roll, as the rolls are generally with the emulsion facing outward.
    With rc papers, there is often no noticeable curl. What can help is slightly wet a fingertip and rub the surface of the paper at a corner. The emulsion side will feel a bit tacky.

  10. #20
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    Re: Unexplicable exposure problem with paper negatives

    Quote Originally Posted by tonyowen View Post
    I dropped a sheet of paper in daylight and later processed it through the developer and fixer. Result a black image so the chemicals worked and the paper is sensitive to light.
    Or did you mean as a way of determining the emulsion side - emulsion side darkens in daylight

    regards
    Tony
    Nope it was a test to see if the paper and the developer were good and to determine if it was " user error " ...
    I'm guessing your paper was installed in your film holders emulsion IN, back OUT .. not an uncommon thing some papers are impossible to tell which side is which
    with some people resorting to licking the paper or a finger to see which side is sticky, curl tests &c.

    My only suggestion, is to install your paper in the film holders the opposite way you are currently installing them and see what happens.. ( and then buy glossy paper )

    Good Luck !
    John
    enjoy your coffee

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