Quote Originally Posted by StoneNYC View Post
So theoretically, if I had some leftover E-6 and no more rolls to process I could run B&W rolls through it and get B&W slides?
Nope, not directly. The biggest difference is the bleach: In E6 you use a (so called rehalogenating) bleach that turns Silver into Silver Bromide. The resulting Silver Bromide gets fixed away together with the Silver Bromide that was never developed by FD or CD. In the end you have a dye image and (ideally) no remaining Silver. In b&w reversal processing you use a bleach that won't touch Silver Bromide, but will convert Silver into a soluble compound, most likely Silver Sulfate. The remaining Silver Bromide will then be converted to Silver by the second dev step in order to form the final image.

If you have left over E6 chemistry, you could do the following in order to process b&w slides. Note that some bathes must still be home brewed or sourced elsewhere:
  1. Process b&w film in E6 FD. Time and temperature may well be different than what you use for E6 processing!
  2. Bleach film in b&w reversal bleach, not with E6 bleach and also not with E6 BLIX. Using the wrong bleach would give you black slides.
  3. Re-expose either with light or with chemical re-exposure bath from E6 if available (E6 3 bath kits have the re-exposure compound in their CD bath so you can omit this step if you use one of these kits)
  4. Develop film with E6 CD. This is a process that goes to completion. Again, time and temperature might be different than what you use for E6. You can test times by watching how long it takes to fully darken a test clip exposed to room light.
  5. Fix away any remaining Silver Halide that didn't develop for whatever reason in the previous steps. You can use E6 fixer if you have a kit with separate bleach&fix, but you can not use a BLIX here, it would remove the whole image. Since color fidelity is a non issue with b&w slides, you can also use b&w fixer. Use fresh and strong fixer here because some films are notorious for their magenta cast if poorly fixed and washed. You don't want that in a slide.
  6. Wash&dry as usual

You can use the following techniques to fine tune your slides:
  • Add Thiocyanate in 1 g/l increments to FD to brighten highlights.
  • Add Potassium/Sodium Bromide in 1 g/l increments to FD to darken shadows.
  • Change exposure, FD time and temperature to change image contrast and brightness.

One thing you could do with BLIX or fixer is test your film for suitability as b&w slide film. Fix or BLIX unexposed film until your are confident the process is complete, then check how much density is left. Some films, most notably the more sensitive films like Delta 3200, have quite a high Dmin which makes them more or less useless for b&w reversal.