PHPP100G

10-0890 100G

Photographers' Formulary

p-Phenylenediamine is the classic superfine-grain film developer. However besides the cautions listed, it requires strong overexposure of the film and a very long developing time, often twenty minutes or more, and even then the contrast of the resulting negatives is rather low. As a result there have been efforts to replace p-phenylenediamine with other agents. One of the more successful is Windisch Superfine-Grain Developer that uses o-Phenylenediamine. This agent also has weak developing properties, but works as a good solvent for silver halide.