Photographic film spectral distribution measuring method for calculating exposure value - using linear summation of main spectral distribution components for different samples

摘要

The spectral distribution measuring method involves analysis of the spectral distributions of a number of film samples, to determine the main spectral distribution components. The light passed through the film is spectrally divided into different wavelength bands, corresponding in number to the main spectral distribution components. The spectral distribution coefficients are obtained by linear summation of the latter, using the photometric values for each wavelength or wavelength band. The main spectral distribution components are obtained by analysis of spectral transmission density distributions for a number of similar film samples. ADVANTAGE - Accurate; compact photometric appts. may be used which does not require defraction grating or several interference filters.