Joe revisits the hydrogen peroxide + citric acid reversal print process he began working with over a year ago, using aged chemistry. Will he achieve consistent, repeatable results?
See the video done by Ethan (of CAMERADACTYL Cameras fame) on the citric acid / peroxide reversal process here: • Direct Positive Revers...
This alternative reversal process was developed by Ricardo Leite in conjunction with Dr. Scott Williams (of caffenol fame), see this PDF: www.filmlabs.org/docs/citric-h...
A quick rundown of the process:
1) Expose print paper in-camera (grade 2 RC I rate at 3 stops more than ISO 3)
2) Fully develop in fresh chemistry to completion (~2 minutes)
3) 30s water rinse
4) 30s in citric acid solution (~3 tsp to 500mL water) face down
5) 1:00 in H2O2 (I'm using 35% H2O2, but 12% also works) face down
(NOTE: drugstore H2O2 is too weak, you need at least ~12%, can be found at health food stores or beauty supply stores for hair bleaching)
6) Repeat steps 4 & 5
7) 30s water rinse
8) Flashing exposure ~5 seconds under bright white light
9) 2nd development to completion - can be done under white lights
10) Final rinse; no need to fix, should not have any residual silver halide left in emulsion
1 сен 2019
