Photographic Emulsion Calibration with the Use of a Digital Computer

Abstract

A computer program, written in Fortran IV, has been developed for the calibration of photographic emulsions using the two-step method of Churchill. Innovations in this program are: (1) the proportional weighting of all points used in the construction of the preliminary curve to their precision of determination; (2) the examination of the preliminary curve of best fit with the rejection of spurious values; and (3) an automatic increase of the degree of the equation used if a random scatter of points about the preliminary curve has not been found. A table relating relative intensities to percent transmittance is printed and a data card containing the coefficients of the emulsion calibration curve is punched.