Some film-noise measurements by diffraction of coherent light.

It is known that the diffraction of coherent light can be used for various spatial-noise measurements including the power-spectrum estimation of photographic emulsions. A number of such measurements are presented. The power spectrum of grain noise is compared with several theoretical models. The spectra of grain and phase noise for overexposed film are obtained. A simple procedure for obtaining the variance of the phase noise of photographic film, assuming gaussian statistics and statistical independence between grain and phase noise, is furnished.