Brush development...what brush?

Discussion in 'B&W: Film, Paper, Chemistry' started by BetterSense, Aug 8, 2013.

  1. BetterSense

    BetterSense Member

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    I have heard that brush development of sheet film gives good even-ness of development. I have even had astrophotographers tell me that brush development was the ONLY way to get truly even negatives.


    What brush? How do you do the brushing?
     
  2. Gerald C Koch

    Gerald C Koch Member

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    Any soft bristled brush with a non-metallic ferrule can be used. Check out an artists supply house.
     
  3. Dave Swinnard

    Dave Swinnard Subscriber

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    Can't speak to the brush issue directly...but

    Speaking of astronomer/photographer... Back in the '70s, as a student at university, I used "swab" development on 4x5 glass plates (astronomical emulsions from Kodak).

    A reasonable amount of developer in an oversize tray and a cotton puff (cotton ball, cotton batting - from pharmacy) that was gently, methodically, and continuously moved over the plate's surface (side to side, up and down, not TOO much pressure - it was to keep the fluid in motion, not scrub the plate) produced a very even development compared to other techniques (no nitrogen-burst development available, just trays - a small department). If I recall correctly, there was also an open-weave rubber mat under the plate to keep it from sliding about and to raise it off the bottom slightly.

    As part of a project, evenness of development was checked by uniformly flashing plates to a moderate density then scanning with a scanning microdensitometer (a large, office filling beast that output as a trace on paper or punched a paper tape). Only the swab development produced a flat scan (indicating even density) across the plate's width and height. All other methods produced unevenness especially near the edges. (developers were MWP-1 and MWP-2).
     
  4. jim appleyard

    jim appleyard Member

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    Lots of types will do, it depends on the effect. soft bristles give you one kind of look, stiff gives you another. Some folks use the foam brushes. You will probably not want a wire brush or anything so stiff that it scratches the emulsion...but then again.
     
  5. bobwysiwyg

    bobwysiwyg Subscriber

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    Why the stipulation for a non-metallic ferrule? Just curious.
     
  6. Hexavalent

    Hexavalent Subscriber

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    Most metallic ferrules are a wonderful source of contamination as they will eventually rust/corrode (sometime very quickly). Only a highly-quality stainless-steel ferrule would likely be 'safe'.
     
  7. Zelph

    Zelph Member

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    Simple Hake brush with wood handle works well. I use it and make sure the brush goes in no other chemicals. Just being safe. Learned this method from a fine Pt/Pd printer who shot 8x10 and used brush development. After trying it I have not gone back to regular or interleaving with 8x10 negatives.