1. A method of remote sensing comprising the steps of forming a plurality of photographic images of a common scene overflown by an airplane or satellite or the like by exposure of different film portions respectively primarily to different zones of the actinic electromagnetic spectrum; developing said images; illuminating the several developed film images individually with lights of selected chromaticities, the chromaticity of the light illuminating at least one of said developed images being substantially different from the chromaticity associated with the corresponding exposing spectral zone for that image; simultaneously displaying the illuminated developed images in registration for evaluation; and individually varying the brightness of the contributions of the several developed images to the display resulting in contrasts, (of differences), from which information about the scene may be easily discerned.