FORMULARY DK-50/DK-50R (Film Developer 50) is a moderately fast developer for commercial and sheet sizes of Plus-X, Pan professional films. The developer produces negatives with normal contrast, average to slightly higher than average graininess. May use with or without dilution. Undiluted developer can process 5 8x10s per liter without replenishment. Diluted developer 1:1 can process 10 8x10s per liter.