Quote Originally Posted by RalphLambrecht View Post
Dan

That's correct. Farmer's Reducer is nothing but potassium ferricyanide (bleach) plus fixer. Using them together or sequentially has the same effect.
However, the mixture has the benefit that one can immediately see the bleaching progress. Unfortunately, it is not very stable due to a chemical reaction between ferri and fixer, causing it to lose its entire strength within 10-15 minutes.


Ian

What is a ferricyanide/bromide bleach?
A Potassium Ferricyanide/Potassium Bromide bleach is a re halogenating bleach, more usually used for toners.

For artwork and complex reduction it's sometimes more useful than Farmers.

Using Potassium Ferricyanide on it's own followed by fixing is quite different in effect to the action of Farmers Reducer.

If you add ferricyanide to commercial fixer it's an agressive bleach particulary if the fixer is ammonium thiosulphate based. However Farmers Reducer uses plain Sodium Thiosulphate and the action is far more gentle and it's useful for lightening shadow details and much slower working.

Ian