On the Point and Line Spread Functions of Photographic Images

The paper describes the three basic functions used to describe the image forming properties of photographic materials. The functions are the line spread function, the point spread function, and the transfer function (spatial frequency response). Only one of the three functions is independent, and therefore three pairs of conjugate relations exist among them. All six relations are given explicitly.The relations are exemplified by deriving the point and line spread functions of Super-XX, Kodachrome, and Microfile film from the transfer function measurements of Schade. The results are given in Figs. 2 and 3. Four different characteristic lengths associated with the spread functions are defined, and their numerical values are given in Table I.