Psychophysical Treatment of Photographic Optics (IV)

Approach to the Evaluation of Defocussed Images by Three Dimensional Test Charts

Abstract

The impression of the defocussed image causes often much discussion in the pictorial photography. Each photographic objective shows its own feature in the defocussed images. A 3-dimensional test chart (This means that the chart has the depth in the object space.) has been made for trial, and as examples of its use measurements and analyses of many defocussed images formed by several photographic objectives have been undertaken. The second moment of area is calculated from the line spread function of each lens, and the normalized moment is compared with that of the normal distribution.