Difference between revisions of "Darkroom Process Notes"

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(Notes on exhaustion of C-41 chemistry)
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** Development time on paper has been ~120s
** Development time on paper has been ~120s
** Not yet tested on film
** Not yet tested on film

Latest revision as of 03:21, 16 January 2019

Many notes about process live on paper sheets or the whiteboard in the darkroom itself, but more useful/long-term things will be copied here for future reference.

(Notes to be copied from the sheets in the darkroom next time I'm there -sen)


Tetenal Colortec C-41 86°F Process[edit]

  • First done 2015-02-15, no issues
  • Mixed per chemical kit instructions
  • Make sure all chemistry is at 86°F before starting.
  • One mixed-up litre is good for exactly 12 rolls of ISO 400+ film.
    • The 12th roll looks fine, the 13th roll is severely degraded.
  • Timing
    • 1min pre-rinse
    • 8min in CD
    • ~30s in stop bath
      • Not absolutely required, but extends the life of the BLIX
    • 6min in BLIX
    • 6min rinse in film washer
    • 1min soak in STAB

Homebrew Chemistry[edit]

Coffee-based Caffenol[edit]

  • Smells extremely bad, avoid doing this again until the darkroom has improved ventilation.
  • Tones the paper slightly sepia-like
  • First two 8x10 prints came out great, then there was an hour delay due to other things coming up, then we did two prints that were very dark and very low contrast no matter what we did. Unsure if it was the time delay causing the developer to break down, or that it was exhausted after two sheets.

Green tea-based Caffenol[edit]

  • Worked great, doesn't smell nearly as bad as the coffee-based solution.
  • Developed 5 sheets over an hour or so and no noticeable degradation over them.
  • Despite looking like a green milkshake, doesn't noticably tone the paper at all.
  • Recipe
    • Part A
      • 450ml 22°C water
      • 10 bags of green tea
      • Let steep for 15 minutes
    • Part B
      • 600ml 22°C water
      • 4 teaspoons of sodium carbonate
    • Mix parts A and B together
      • If you mix all the ingredients at once rather than as two parts, it's very hard to make the sodium carbonate dissolve
    • Add 3 teaspoons of vitamin C
  • Timing
    • Development time on paper has been ~120s
    • Not yet tested on film