Photographers' Formulary Phenidone Extended Range Developer (POTA), Makes 1Lt

Phenidone Extended Range Developer (POTA) is a very soft-working Phenidone-based developer. With low-speed films, POTA is capable of recording 15 to 20 stops of exposure range. When used on fine grain, high contrast copy films, POTA produces negatives with near normal contrast and extremely fine grain. Enlargements of 20-30 times are possible. This kit makes 1 liter of working solution which has a shelf life of only 1 hour.