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Ansco 310 Farmer’s Reducer

FormulasThis is a cutting reducer for lessening the density of heavy negatives and at the same time increasing their contrast. It is especially valuable for reproduction films to clear the whites.


Solution 1

Sodium Thiosulfate 240 g
Water to make 1 L


Solution 2

Ferricyanide 19 g
Water to make 250 ml


For use, mix one part Solution 2 and fourparts Solution 1 in 32 parts water. Solutions 1 and 2 should be stored separately and mixed immediately before use.


From Ansco Formulas for Black and White Film by GAF, 1948 – Formulas are provided for historical reference. They may not work well with modern films and papers. Some of the chemicals can be dangerous. As with all photographic processes, be careful.