There should be because the sodium thiosulphate and ferricyanide work together, but it depends what you're trying to retouch.
Originally Posted by RalphLambrecht
If you're just using a bleach on the highlights then the differences are not as significant, Farmers reducer exhausts quite quickly in use which helps the control-ability when retouching. The prescence of the thiosulphate help particularly when reducing shadow areas.
I seem to remember in a previous thread you used ferricyanide & rapid fixer as a reducer, and Ron Mowrey (PE) pointing out the aggressive nature of the combination.
Perhaps a simpler explanation is that Ferricyanide on it's own attacks the smaller grains first, that's why it's used with or without bromide for split toning, but with Thiosulphate added Farmers Reducers attacks the larger "black" grains as well at the same time.
If you put a print in a ferricyanide/bromide bleach some blacks don't bleach until the last moment, which is what's used in split toning, you control the time to pull from the bleach. Put a print in fresh Farmer's and leave it and it'll lighten more progressively across all the tones - very different.
Farmer's cannot contain commercial fixer only plain sodium thiosulphate anything else is very different in behaviour.
Last edited by Ian Grant; 10-01-2010 at 02:21 PM. Click to view previous post history.