The Effect of Exposure and Development on the Quality of Variable Width Photographic Sound Recording
This paper deals with the dependence of the quality of variable width recording on the conditions of exposure and development. When the widths of the images employed in recording or reproducing are comparable with the wavelength of the record the exposed portion of the record is not uniformly exposed. The record is attenuated in amplitude as the frequency is increased, and harmonics are introduced whose relative intensities depend on the contrast of development and on the frequency. When the exposure of the record occupies the linear range of the H & D curve, and when the product of the gammas of the negative and the positive is equal to unity, the record is practically free from spurious harmonics. The amount of non-linear distortion is calculated for the case when the over-all gamma is equal to two; and it is shown that Cook's2 analysis of the aperture effect gives a superior limit to the distortion obtainable by overexposure or by over- or underdevelopment. The effect of the unavoidable non-uniform illumination of the images is considered.
- Print ISSN
- 0097-5834
- Published
- 1931-11
- Content type
- Original Research
- DOI
- 10.5594/J07506