Method of estimating spectral distribution of film and method of determining exposure amount

摘要

A plurality of principal-component spectral distributions are determined in advance by analyzing spectral distributions of a multiplicity of sample films; light transmitted through a film to be estimated is measured by spectrally diffracting the transmitted light into wavelengths of different bands or into different wavelength bands the number of the wavelengths or wavelength bands being equivalent to that of the plurality of principal-component spectral distributions; coefficients for expressing the spectral distribution of the film to be estimated as a linear sum of the plurality of principal-component spectral distributions are determined on the basis of photometric values of the respective wavelengths wavelength bands and the plurality of, principal-component spectral distributions; and the spectral distribution of the film to be estimated is estimated by determining the linear sum of the plurality of principal-component spectral distributions by using the coefficients obtained. On the basic of the spectral distribution estimated and by using an effective spectral sensitivity distribution of the copying light-sensitive material, a calculation is made of a transmission density which is equivalent to a transmission density obtained when an image on the film to be printed is photometrically measured by a photometric device having a spectral sensitivity distribution identical to a spectral sensitivity distribution of the copying light-sensitive material; and exposure amount for printing the image on the film to be printed onto the light-sensitive material is determined on the basis of the transmission density calculated.