A discussion is given of some difficulties encountered in the quantitative evaluation of photographic line patterns, particularly in such cases where integrated intensities are required. As a result of this discussion two methods applicable to absorption densitometry are proposed intended to facilitate such measurements and to reduce the errors involved. One method consists in recording with the densitometer tracing of the line pattern a tracing of a stepped wedge which serves to establish correlation between the densitometer record and a standard conversion curve by projecting the steps in superposition with the corresponding points of the curve. The other consists in recording the line pattern on a moving plate or film which has the result of reducing the peak densities and improving the line shape with but a small increase of line width and exposure time. The first method is equally applicable to the visible and x-ray range, the second method is primarily intended for x-ray patterns.
J. C. M. BRENTANO, "The Quantitative Evaluation of Photographic Line Patterns," J. Opt. Soc. Am. 35, 382-385 (1945)