Pyrocat HD film developer

Description

Sandy King’s pyrocatechin developer in two parts: A and B are mixed immediately before use, 1+1+50. It stains the image, gives high sharpness and yields a negative that suits both scanning and contact printing.

What the stain does

Pyrocatechin oxidises as it develops and dyes the gelatin a greenish-brown in proportion to the silver density. That dye adds density where silver already is, so highlights compress on their own and grain is partly masked. It is why pyrogallol and pyrocatechin developers are still used for large format.

Why two parts

Solutions A and B are stable apart and thoroughly unstable together. They are mixed just before the tank is filled and poured away after one development — which is why every size here is two bottles.

Questions and answers

Can a stained negative be scanned?

Yes. The stain sits in the green-brown range a scanner handles well; the blue channel is an option if you need more separation.