A Comparison of the Square Wave Response of Three Microscopes Commonly Used in Photointerpretation.

The optical performance of three steromicroscopes commonly used for photointerpretation is described in terms of magnification, field of view, and Square Wave Response SqWR. For a given field size, the Square Wave Response can be used to compare the amount of information in the image of each microscope. The Square Wave Response was determined by scanning a square wave test target at four field positions for each of four field sizes corresponding to magnifications of 6, 12, 25 and 50X. The measured Square Wave Response was used to evaluate the relative ability of each microscope to perform two typical photointerpretation tasks 1 scanning or searching for a target, and 2 detailed viewing of a target.