Sometimes a photographer's data sheet will accompany film that enters your imaging facility to be processed. The photographer's data sheet will provide you with information on how the film was shot, lighting conditions, and specific processing instructions. When a photographer's data sheet accompanies the film or job order, you should process the materials specified by the form.

Cleaning Up

After processing, the darkroom and all equipment must be cleaned up immediately. Rinse thoroughly all processing equipment: tanks, reels, hangers, thermometers, funnels, and so forth, in clean, warm water. Place the clean equipment where it can dry before it is needed for the next processing run. Always keep the processing room shipshape.

REVERSAL PROCESSING

Normal processing of black-and-white film produces a negative; from this negative, a positive is made. However, by using the reversal process, you can produce a positive image directly on the black-and-white film.

In the reversal process, a negative image is first obtained by developing the original latent image in a developer that contains a silver halide solvent. This developer dissolves some of the excess silver halides. After leaving the developer, the negative image is dissolved away in a bleach bath. The silver halides remaining are chemically exposed (fogged) and developed by a second developer that provides the positive image.

Not all black-and-white films reverse well. Films that reverse well are Kodak Direct Positive Panchromatic Film 5246 (35mm), T-max 100 Direct Positive Film, and Kodak Technical Pan Films (35mm). Instructions for reversal processing of these films can be found in the Photo-Lab-Index.