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Contrast Control

As I've said potassium chloride added to the ferric oxalate is the traditional method of contrast control. I find it adds a sort of lumpy grain to the image and also cools down the image. I NEVER use it! Some people also feel that adding platinum to the emulsion is a way to add contrast. I hate to disagree but even though Platinum is somewhat more contrasty than Palladium the main reason to vary the amount of Platinum to Palladium is for color issues not contrast control.

I have found the following to be quite effective when I can not get the necessary contrast from my negative:

DICHROMATE METHOD OF CONTROLLING CONTRAST
This seems to be the best solution to controlling contrast in the printing if you just can't make your negative contrasty enough! I now make sure, when ever possible, that my negs have enough contrast so that I can use a #1 - #3 mixture always!!!

SODIUM DICHROMATE FOR CONTRAST CONTROL
Keep each contrast developer labeled in a separate bottle do not interchange .YOU MUST USE POTASSIUM OXALATE DEVELOPER WITH THE DICHROMATE METHOD! YOU ALSO MUST USE GLOVES WHEN WORKING IN THIS DEVELOPER! CHECK OUT MSDS'S AND RELATED INFO BEFORE USING THIS OR ANY OTHER CHEMICALS! ALL PAPERS ARE COATED WITH NO SOLUTION #2!!!

To make a 50% solution of Sodium Dichromate add 50 grams of it to 100 mls of very hot water and shake, shake, shake it takes along time to go into solution and you may want to reheat it. It will last forever.

You can change these formulas to fit your own contrast ranges but remember to keep each different mixture labeled and in it's own jug. Also this stuff is not good for you. Read MSDS!!!