IMPORTANT: - I no longer recommend the use of dichromate bleach. It's beautiful, but REALLY toxic. I have another method that doesn't require this horrible chemical.
As delightful as Harman Direct Positive paper is it can get quite expensive and the contrast is very high. As an alternative, I've been waiting to try reversal processing of standard negative paper.
Having tried the process before with hydrogen peroxide and citric acid (with poor and slow results), I contacted @hackaninstant on Instagram to see what James could recommend. He suggested using dichromate bleach, which I had to mix up from powder, with a little sulphuric acid, and to make a sodium sulphite clearing bath from powder, too.
Apparently, this is similar to the old photo booth process.
1. Expose paper at ISO 3, plus two stops (so around ISO 0.75)
2. Develop normally (I used Champion Suprol 1+9, 2 mins)
3. Stop (acid stop, 1+19, 1 minute)
4. Wash
5. Dichromate bleach until clear (this only took about 20 seconds!)
6. Sodium sulphite clearing bath (1 minute)
7. Re-expose to light (it'd been in the light since the wash)
8. Re-develop (same as step 2)
9. Fix (Ilford Rapid Fix 1+4, 2 minutes)
10. Wash and dry
EDIT 15TH OCT 2023:
Use ISO 1-3, not 0.75
Stop for 10 secs, not 1 min
No need to fix
I'm astonished by the tones and how incredible it looks out of the box. No pre-flashing done here on this one but the contrast seems better controlled than DP. And Kentmere is much cheaper 🙂👍
Definitely one to enjoy!
This is amazing! so once you to your initital wash you expose to light? For any particuar length of time?