With the dichroamte control method you basically match the amount of dichromate you add to the developer to the density range of your negative. For that reason you need to have a separate solution that covers the varying DR of your negatives. I develop my in-camera negatives to a DR of about 1.8, and try to get the same contrast with digital negatives. This limits the number of separate solutions I need to have on hand to two or three.

Although your experience may be slightly different from mine due to paper choice and chemistry here is the method of control I keep for printing with pure palladium.

1. Negative DR --1.80 1ml of a 5% potassium dichromate solution per liter of developer.

2. Negative DR -- 1.60 2ml of the 5% PD solution per liter.

3. Negative DR -- 1.40 4 ml of the 5% PD solution.

4. Negative DR -- 1.20 8 ml of the 5% PD solution.

I don't recommend using more dichromate than this because of the increased grainy look that results.

Drops vary also, but generally 1ml equals about 20 drops.


Quote Originally Posted by Shinnya

I should do a little search before I post a question. I did find something about bleaching if higher contrast developer like #4 is used with Pd prints. I am mixing 1:9 (pt/pd). It certainly does look lighter in shadow. Is this because of bleaching?

Also, about the amount of dichromate, I am getting different information. Some say 1 drop per 200ml and others say 1ml per 200ml. My understanding is that 1 drop is 0.05ml. It does not sounds like they are talking about the same amount...

Thanks again.