Cartome FM5-20 Camouflage, Basic Principles War Department, February 1944

FIGURE 18 1 -- Panchromatic film -- the most common kind used in aerial photography. The aerial photo interpreter gathers information from size, shape, shadow, and tone of objects. FIGURE 18 2-- An infrared photograph of the same area shows up certain camouflage areas. Artificial vegetation, for example, is revealed by this infrared photograph.
FIGURE 18 3-- Color photography detects faulty matching of color in camouflage. Many clues which evade the panchromatic film may be picked up by color film. But color film has many operational disadvantages and is not commonly used.