What is the approximate ISO rating of Rockland emulsions?
Unlike conventional black and white films, liquid emulsions are not panchromatic (sensitive to all colors) but only to blue light. If you are using the emulsion in a camera, put a piece of blue acetate (any shade is okay) in front your exposure meter. Once the exposure is calibrated, you can expose consistently from shot to shot, as you are measuring only blue light. To calibrate, start test exposures with an arbitrary ISO or ASA setting such as the low double digits. Note that sensitivity may vary from batch to batch, represented by the date stamped on the box. Back to top How can I increase the contrast of the emulsion? You can get maximum contrast and density by sensitizing the emulsion with a small amount of developer. One method is to add exactly one part of working developer (not concentrate) to 10 parts of emulsion before use. Sensitize only as much emulsion as you plan to use within one day, as the mixture will not keep. Another method is to sensitize the emulsion after coating