Marks on Negative – Opinions Appreciated

Discussion in 'Film and Processing' started by benmabry, Jan 30, 2021.

  1. I've started processing BW film at home and my last two rolls have these marks. What might be causing this? I'm using Cinestill DF96 Monobath.
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    Last edited: Jan 30, 2021
  2. They look like pouring marks from not filling the tank fast enough. Are you using a drum or rotary processor by any chance?

    Give us a full run down of your equipment and procedure, and we might be able to help further.

    Monobath - urrrgh!
    First thing I'd suggest is using a separate developer and fixer. Nobody uses film for its convenience factor.
  3. I'm using a small Jobo tank and a constant inversion agitation (per the DF96 instructions). I follow the Ilford rinse method with tap water and a few drops of wetting agent. Hang, squeegee, dry. I'm pouring straight from the bottle into the funnel of the tank so it's only 5 or so seconds between pouring, securing the lid, and beginning agitation.

    These were my 11th and 12th rolls on the same chemistry and although the bottle claims 16 before exhaustion, it's looking a little grimy. Could it be due to exhaustion?

    Also, I washed the tank to remove any dust or dirt before processing. If it wasn't properly dried would residual water from my washing cause marks?

    Point taken on the convenience! I plan on switching to separate developer and fixer once I can figure out what is causing these ugly marks.

    Thanks for your input!
  4. Almost certainly.

    Also, how full is the tank?
    These really do look like flow marks, as if the film hasn't been fully covered.
  5. I follow the measuring instructions on the side of the Jobo tank. So, 485ml for inversion (240ml for rotation). It feels full but with a bit of room for the liquid to move around.
  6. That sounds right. Having the tank brim-full will actually inhibit agitation, because it's the airspace bubbling past the film that does the work of mixing stale with fresh developer.

    You're not by any chance following the dumb YouTube videos that show a slo-mo figure-of-eight wrist roll for agitation, are you?

    That's completely wrong, and could result in creating standing waves in the tank.

    All that's needed is a fairly quick inversion of the tank; hold it upside down for a slow count of two or three; then right the tank again. Anything else is a waste of effort, and inefficient. You're not doing Tai-Chi or Yoga on behalf of the film!

    For 'continuous' agitation you only need to repeat the inversions 5 or 6 times a minute. And beyond 4 will probably make absolutely no difference to the appearance of the film.
  7. Ha! My agitation action may be my problem then as I am doing compound flip/spin movement. I'll try the simpler method the next time I'm developing and report back. Thanks!
  8. Those idiotic YouTubers ought to be sued for spreading misinformation and ruining countless films!

    I have no idea where that dumb figure-of-eight action came from. Nobody of any note has done that, or advised that since I started tank-developing film when I was aged 11... and that's over 60 years ago now!
  9. The way I was taught to agitate:

    Pick up tank, flip over and hold while listening to the air shift, wait two seconds, and then flip back over, setting down on the counter with a bit of a "smack" to dislodge any air bubbles that may have ended up on the film in the process.

    It's worked perfectly fine for me!
    benmabry and rodeo_joe|1 like this.

  10. So, I developed my first role with Ilford chemistry and the tried-and-true method of agitation – Perfection! There are no ugly marks and the negatives look quite good compared to the ones developed in the monobath. It was totally worth the extra 5 minutes.

    Thank you!
  11. You're welcome.
    It ain't been used for over a century for no reason!:rolleyes:
  12. I was just reading the TMax data sheet from 1992.
    (Remember when you actually got a piece of paper in the box!)

    "Use vigorous agitation at 30 second intervals."

    I am not sure that I ever agitated at what I might call vigorous,
    maybe like a bartender with a cocktail shaker? (not stirred)
  13. One person's idea of 'vigorous' isn't the next person's.

    Like a cocktail shaker - no, definitely not.

    Just inverting the tank swiftly is about right. What you're trying to do is emulate Nitrogen-burst agitation by letting the airspace in the tank evenly percolate (bubble) past the film surface. Short of lift-drain-and-dunk, it's about as efficient a method of agitation as you can get in an enclosed tank.

    As James Bond requested - "Shaken, not stirred."..... but not too shaken.
  14. Yes, I was surprised to see Kodak's use of the word.

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