Coherent optical power spectra of photographic materials.
Measurements of the light scattering properties of nine films and plates commonly used in holography and optical processing were made using a calibrated coherent optical Fourier transform computer. On the basis of the magnitude and shape of the scattered light power spectrum, the measured films are divided into two classes, the first of which includes the low resolution films with high scattering, and the second of which includes the high resolution, low noise, films, and plates. Film spectra of the first category decrease rapidly with spatial frequency to about 25 cycles/mm and are constant to 200 cycles/mm, the maximum frequency to which measurements were made. Spectra in the second category were typically more than 10 dB lower in intensity than those of the first at any given spatial frequency, and these spectra decreased monotonically throughout the region of measurement. On the basis of both the spectral measurements and measurements of the specular and diffuse densities, the Callier Q coefficient is evaluated as one figure of merit for predicting the signal-to-noise properties of materials for optical processing.
Brandt
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GB