Agitation/Development issues? Streaks on negatives.

Discussion in 'Film and Processing' started by pearsonripley, Nov 17, 2020.

  1. I have been getting these streaks on my color negatives. They are visible in the sky, on a wall or in any negative space. My process is as follows:

    I have been using Kodak Flexicolor chemistry. I use the sous vide method with a stainless steel 500ml tank. I put 435ml of developer in the tank, bring it to temp and drop the reel into the heated developer with the lights off, then put on the lid, switch on the light and agitate according to the Kodak Flexicolor instructions for small tank developing (1st 30 seconds, then 2 inversions every 15s). I agitate by inverting with a slight rotation, also according to Kodak.

    These are Kodak Portra 120 negatives, shot on a Mamiya RZ67, scanned at home. The issue is not in the scan, it is visible on the light table. My only thought is insufficient agitation or not enough developer in the tank?

    Pardon the edits, just wanted to make the streaks visible. Thanks everyone!

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    Last edited: Nov 17, 2020
  2. Great job pearson, love the last photo.

    Those marks are most likely drying marks.

    You might try outstretching the film at 45 degrees so as to let the stabilizer run to one edge of the film and drain to the bottom corner, then touch the bottom corner onto a sheet of paper towel to soak up the excess stabilizer. Hold it there for a few moments allowing as much excess as possible to drain from the film. An alternative is to squeegee the film, but it's not recommended because it may leave scratches.
  3. Thanks Kmac! That is what I thought initially as I have had some issues with drying marks (I think mostly after stretching the stabilizer too far), but there is nothing showing on the surface of the negatives like drying marks normally do. Could drying be an issue without showing on the surface? I believe this is a density issue.
  4. Interesting.
    How do you create and maintain a vacuum in the developing tank?:cool:

    The marks could also be caused by large air bubbles being momentarily trapped in the spiral before the first agitation. This can happen if you quickly plunge a loaded spiral into a small tank of developer.

    Almost nobody drops the loaded spiral into a pre-filled small tank. Most people pour the developer into the loaded tank+spiral. The filling and emptying times are short enough to be insignificant.

    Drying marks are another possibility, but the orientation of those marks look as if they could only be caused by drying the film sideways.

    FWIW. People were home developing colour film successfully long before fancy "boil in the bag" kitchen equipment was invented. All that's needed is a bowl of water brought to the right temperature by mixing hot and cold water from the tap.

    Only the developer temperature(s) are critical, and a simple plastic washing-up bowl of water has sufficient thermal mass to keep the temperature stable for the length of a colour development time.

    Obviously the bottles or measures of solution need to be tempered before use.
  5. Thanks for the response Joe. I suppose it could be an air bubble as a result of the drop but the right angle visible in the second shot makes me feel otherwise. I'll load a reel up with some test film and look for air bubbles next time I'm in the darkroom. The agitation has begun within a few seconds of the reel going in, whereas it takes at least 20 seconds (10% of the total developing time) to get the liquid into my tank/lid when pouring, so I feel like pouring the developer would have a more adverse effect by that logic.

    My new thought is that I might be spending too much time trying to get the developer out of the tank. I try to shake it out pretty thoroughly to avoid too much carry over but I think I just need to get the majority out and get the bleach in more quickly.

    And not sure what you have against the sous vide! They aren't so fancy, Craigslist is loaded with them for 30 bucks.
  6. Only poking a little fun at the fad for making cooking a high-tech faff these days. With a gadget for every purpose.

    I recently watched a TV chef insist that his beef be cooked at precisely 86.4 C in a Sous-vide machine. It made me wonder what he did before those fancy boil-in-the-bag machines were invented. And how he arrived at that ridiculously precise temperature?

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