BIlford Perceptol Fine Grain Developer for Black & White Film, Powder to Make 1 Liter. ReviewbP PP Ilford Perceptol Fine Grain Developer for Black & White Film, Powder to Make 1 Liter. PAn Extra Fine Grain Film Developer which gives Excellent Image Quality.PDesigned for Use When Very Fine Grain Negatives are Required and a Decrease in Film Speed is Not Important.