Negative Processing Chemistry Research

Some links to lower-toxicity recipes for dev/stop/fix, with some price and source exploration:

Chems

Dev

Ascorbic Acid (vitamin C)

225g - $13 - ebay - $0.057/g
1000g - $40 - ebay - $0.040/g
500g - $23 - ebay - $0.046/g
450g - $35 - ebay - $0.077/g
225g - $17 - ebay - $0.075/g
450g - $20 - ebay - $0.044/g
900g - $30 - ebay - $0.033/g

Sodium Carbonate (Soda Ash)

500g - $40 - ebay - $0.080/g
680g - $37 - ebay - $0.054/g
1000g - $30 - ebay - $0.030/g
100g - $5 - ebay - $0.050/g
500g - $12 - ebay - $0.024/g

Stop

As the developer isn't as aggressive, we can get away with water bath for stop.

Fix (non-hardening)

Sodium thiosulfate (pentahydrate/crystalline) - [FIX]

400g - $37 - etsy - $0.0925/g
113g - $7 - ebay - 113g – $0.0619/g
2500g - $50 - ebay - $0.0200/g
1360g - $55 - ebay - $0.0404/g
1360g - $50 - ebay - $0.0368/g
450g - $15 - ebay - $0.0333/g

Sodium sulfite (anhydrous) - [FIX]Increases shelf-life of fix, not necessary

30g - $40 - ebay - $1.33/g
500g - $150 - ebay - $0.30/g
500g - $50 - ebay - $0.10/g
450g - $30 - ebay - $0.07/g
450g - $23 - ebay - $0.05/g
225g - $16 - ebay - $0.07/g
450g - $14 - ebay - $0.03/g
100g - $10 - ebay - $0.10/g

Ascorbic Acid [DEV]

225g - $13 - ebay - $0.057/g
1000g - $40 - ebay - $0.040/g
500g - $23 - ebay - $0.046/g
450g - $35 - ebay - $0.077/g
225g - $17 - ebay - $0.075/g
450g - $20 - ebay - $0.044/g
900g - $30 - ebay - $0.033/g

Sodium Carbonate [DEV]

500g - $40 - ebay - $0.080/g
680g - $37 - ebay - $0.054/g
1000g - $30 - ebay - $0.030/g
100g - $5 - ebay - $0.050/g
500g - $12 - ebay - $0.024/g

Developer

Caffinol

Articles

https://petapixel.com/caffenol-developing-film-with-coffee/

https://www.35mmc.com/18/08/2020/polyphenol-developer-alternatives-a-world-full-of-options-by-daniel-keating/

Possibly with espresso given that we have coffee roasting and an espresso machine?

Stop

Fixer

Kodak F-24 based recipe

• Sodium thiosulfate (pentahydrate/crystalline): 240g
• Sodium sulfite (anhydrous): 15g
  • preservative, keeps the bath from oxidizing/degrading between uses
• Water (warm, ~40°C to help dissolution) to make 1L total

Equipment

• Changing bag
• Measuring stuff
  • 1x 250ml graduated cylinder
  • scale
• PPE
  • Apron from basement
  • Goggles
  • Nitrile gloves from basement
• Tanks
  • 3x 2-reel 35mm steel
  • 3x 1-reeel 35mm steel
• Reels
  • ?x 35mm steel
  • 2x 16mm steel
  • 120/220
• Thermometer