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Thread: Identifying cause of streaks on BW negatives

  1. #1

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    Question Identifying cause of streaks on BW negatives

    Hello all,

    I have a problem that I haven't been able to solve on my own, so I'm turning to you for help.

    Important facts:
    • Film: Ilford Delta 100 4x5
    • Tray development: soak for 2 minutes in water, EcoPro dev, water stop bath, TF-4 rapid fixer
    • When I place the negatives in the initial soak tray, I place each one individually and submerge it fully before placing the next negative in the soak tray so they do not stick together.


    In the attached image, I have two more-or-less identical negatives. They were both processed in the same manner but at different times. I generally develop 3 or 4 negatives at a time in trays by carefully pulling the bottom-most negative out and laying it gently on top of the stack. My dev times are usually 7:30 to 9:00 minutes, and I achieve most of my agitation through the shuffling of the negatives. (That is, I don't rock the trays very often while developing.)

    As you can see, the negative on the right has a few odd streaks that are noticeable in the sky, while the negative on the left doesn't appear to have any streaks. Looking through my catalog of negatives, I find these streaks are somewhat common. I have also attached a crop of the area in question. Further, I have provided direct links to a Flickr page since I can't figure out how to show these images in full size in this forum.

    Comparison: https://flic.kr/p/2o3dL7a
    Crop: https://flic.kr/p/2o3cu11

    Click image for larger version. 

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    Click image for larger version. 

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    I have no formal darkroom training, so when things like this come up, it raises a few questions:
    • Is this normal for film, and I just have to deal with it?
    • Is there something that I need to correct in my development procedure?


    Thank you,
    John

  2. #2

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    Re: Identifying cause of streaks on BW negatives

    Was the sky clear/featureless? Asking because I see lots of streak-type artifacts in both negatives and it's difficult to know which are flaws and which might have been things like wispy clouds.

    Agitation of sheet film in trays usually takes some experimentation/practice to get right, and it can sometimes vary with the type of film. I don't use the shuffling method but it is a time-tested method that should work once you get any issues sorted out. I'm noting a few things in your routine that could potentially cause issues:

    1. I would give a longer time in the pre-soak, with agitation, especially for Ilford films. My preferred pre-soaking time is five minutes

    2. You say during development when agitating you pull a negative from the bottom of the stack and lay it gently on top. I think once you lay it on top you need to gently push it down slightly to ensure it is covered with developer. Most people gently push it below the surface, sometimes with a light side to side sort of motion, or gently pushing down on various areas of the sheet to prevent an inrush of developer around the edges of the sheet

    3. Every so often while shuffling it is common practice to rotate the films or tray to change the direction in which you pull the sheets from the bottom of the stack

    4. If you are using an alkaline fixer (TF-4), it is advisable to use a standard acid stop bath after development for say at least a minute and/or a thorough water rinse (not just to stop the developer absorbed in the emulsion, but to remove it/significantly dilute it). Otherwise there is a risk development can restart temporarily in the alkaline fixer, which could theoretically cause various problems

    I don't want to overcomplicate the issue. Tray development using the shuffle method should be totally doable and is actually one of the better methods.

    A member here by the name of Doremus Scudder usually responds to threads like this with his detailed tray shuffling technique so hopefully he will see this. It might help you solve any problems you are having.

  3. #3

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    Re: Identifying cause of streaks on BW negatives

    They almost look like hairs to me. Like you lost some hair and it fell into the tray while developing. I've never presoaked my Ilford films, though I do presoak foma and Kodak because they have heavy anti halation layers.
    Last edited by jtomasella; 30-Nov-2022 at 06:41. Reason: spelling

  4. #4

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    Re: Identifying cause of streaks on BW negatives

    Michael,

    Thanks for the reply.

    The images do have thin, wispy clouds in the skies. The streaks I am referring to are in the right negative in the circled area. It will be easier to see in the cropped image. In general, the clouds are angled from lower left to upper right, while the streaks move in different directions. I hope this helps.

    I have been tray developing 4x5s and 8x10 for a few years now, always using trays and the shuffle method. For the most part, it works well for me. I very rarely have scratches, and I am usually pleased with my results.

    1. I can certainly give this a try. I have not yet experimented with longer presoak times.

    2. I should have provided more details. After I place a negative on top, I do gently push the stack back into the developer and then rock the tray slightly. Thus, I don't believe this to be the cause.

    3. I can't think of a time when I have ever rotated my negatives while developing. This sounds like a worthwhile step to add to my procedure to ensure more even development.

    4. I stopped using acid stop bath because I wanted to reduce my chemical usage. But if there is a possibility of some lingering developer continuing during or after the stop bath step, then I think I need to revisit this. Since the streaks exhibit different tonality than the surrounding sky, I can see how this might be the culprit.

  5. #5

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    Re: Identifying cause of streaks on BW negatives

    Hi John, it's really hard to say if number (4) is the problem or not but you can forgo the acid stop bath as long as the water rinse after development is thorough. It would also be good to use a relatively large volume of water (say in a larger tray) for that step. Then again this may have nothing to do with the problem you're having so I don't want to overstate the case.

    I see what you mean now - the thinner streaks/lines that are curvy and moving in random directions relative to the wispy clouds. Puzzling. Hopefully others will chime in here.

    Quote Originally Posted by jemery View Post
    Michael,

    Thanks for the reply.

    The images do have thin, wispy clouds in the skies. The streaks I am referring to are in the right negative in the circled area. It will be easier to see in the cropped image. In general, the clouds are angled from lower left to upper right, while the streaks move in different directions. I hope this helps.

    I have been tray developing 4x5s and 8x10 for a few years now, always using trays and the shuffle method. For the most part, it works well for me. I very rarely have scratches, and I am usually pleased with my results.

    1. I can certainly give this a try. I have not yet experimented with longer presoak times.

    2. I should have provided more details. After I place a negative on top, I do gently push the stack back into the developer and then rock the tray slightly. Thus, I don't believe this to be the cause.

    3. I can't think of a time when I have ever rotated my negatives while developing. This sounds like a worthwhile step to add to my procedure to ensure more even development.

    4. I stopped using acid stop bath because I wanted to reduce my chemical usage. But if there is a possibility of some lingering developer continuing during or after the stop bath step, then I think I need to revisit this. Since the streaks exhibit different tonality than the surrounding sky, I can see how this might be the culprit.

  6. #6

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    Re: Identifying cause of streaks on BW negatives

    Looking it appears the more vertical lines are the problem. Looks as if it is pressure marks on the emulsion as you shuffle and push down the negative.
    Have seen it in negatives and solved it going to one at a time tray developing. Takes more time but clean negatives are worth it.
    ” Never attribute to inspiration that which can be adequately explained by delusion”.

  7. #7

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    Re: Identifying cause of streaks on BW negatives

    John,

    Michael has given you about all the advice that I would, but I'll chime in anyway, since he summoned me

    Your shuffle technique seems fine, although I might add rotating the sheets to your regime. If you want to see my detailed explanation of my shuffle technique, you can find it in post #9 here: https://www.largeformatphotography.i...ssing-Problems

    I can only speculate and add a couple more things to check.

    First, the streaks almost seem to me to be mechanical damage, i.e., damage to the emulsion from bending or kinking the sheet, which then causes it to develop with more density. Be sure you aren't stressing the film when loading, unloading, submerging them in the trays, etc.

    I had problems with redevelopment in the alkaline fix (TF-4 too, coincidentally) in conjunction with a tiny light leak near the fixer tray. I was using an acid stop too, but the carried-over developer was reactivated in the fix and developed areas that were randomly exposed to an almost unnoticeable light leak. Do make sure your darkroom is dark and don't turn on the white light till at least halfway through your fixing time to prevent this problem. Check around your developer tray too, just to be on the safe side.

    I, too, would recommend a longer soak. Some Ilford films have surfactants built in to help the developer absorb into the emulsion quickly and evenly. If you only soak some of that away, but some vestiges stay, that could be a cause of unevenness. I now like three to five minutes of pre-soak time after immersing the last sheet of a batch into the pre-soak tray. This might be something to try first.

    I had a negative once with strange diagonal streaks in the sky area in one corner. I couldn't for the life of me figure out what could have caused them till I saw a cell-phone photo of the scene that I just happened to make as well. They were clouds... They just looked too regular and striated for me to accept that at first. Maybe your streaks were actually there too?

    And, lastly, make sure you immerse each sheet into the developer tray fully and give them a little swish or whatever to make sure the developer comes into quick and even contact with the film surface before you introduce the next sheet. Plopping down another sheet too soon and without agitating the previous sheet somewhat can trap water between the sheets and keep developer from reaching some areas until the next shuffle. FWIW, I figure out my shuffle interval based on once through the stack every 30 seconds. So, with six sheets, that's five seconds per shuffle. When initially introducing the film into the developer, I would then put them in separately in five-second intervals, agitating for a few seconds before the next sheet. I keep track of sheet one (notch turned 180° from the rest of the stack) so I can end up with it on the bottom of the stack. Then, I pull the stack from the developer, drain and fan it in my hands like a hand of cards. The sheets go into the stop one-at-a-time starting from the bottom of the stack and in the same order that they went into the developer. That's a bit of overkill to ensure that each sheet gets exactly the same development time and also ensures that they get agitated a bit in the stop before the next sheet hits. That keeps developer from being trapped between sheets and continuing to work. Since you use a water-stop, this might be really helpful. Really, though, an acid stop works really well with the alkaline fixers.

    This got longer than I had anticipated. Hope it helps,

    Doremus

  8. #8

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    Re: Identifying cause of streaks on BW negatives

    Doremus,

    Thank you very much for your detailed answer (and for the many other responses of yours I have read on this forum).

    After reading the responses here, I will certainly add in a rotation to the negatives as I shuffle through. This is an easy change to make.

    I try to be extremely careful when I load and unload my film holders, as well as when I place the negatives into the various baths. I can't rule this out, but I don't think it is the culprit here. In any case, I'll pay extra close attention to my film handling... it can't hurt.

    It's your last paragraph that makes me stop and think. With my current procedure, I remove all the negatives from the presoak tray and place them all in the developer at once. I will practice placing the negatives into the developer in intervals as described. Further, it sounds like going back to an acid stop bath is a worthwhile move.

  9. #9

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    Re: Identifying cause of streaks on BW negatives

    Quote Originally Posted by Willie View Post
    Looking it appears the more vertical lines are the problem. Looks as if it is pressure marks on the emulsion as you shuffle and push down the negative.
    Have seen it in negatives and solved it going to one at a time tray developing. Takes more time but clean negatives are worth it.
    This brings up a question that I've had but haven't bothered to look up:

    I know that developer is a one-shot chemical, but would I be able to develop a single sheet and then immediately afterward develop another sheet?

  10. #10

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    Re: Identifying cause of streaks on BW negatives

    Quote Originally Posted by jemery View Post
    This brings up a question that I've had but haven't bothered to look up:

    I know that developer is a one-shot chemical, but would I be able to develop a single sheet and then immediately afterward develop another sheet?
    Yes you can certainly do that. However if you do one sheet at a time my advice would be to use the same agitation method (ie manually shuffling the single sheet). Don't do tray rocking.

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