The taking of aerial photographs of rock exposures and of the ground surface for purposes of geologic interpretation. The photographs may be taken vertically, or at a high-oblique or low-oblique angle, and may be assembled like a mosaic to provide a picture of a large area. Stereoscopic cameras (two cameras within a single body) may be used to produce pairs of pictures that provide three-dimensional pictures when observed through a stereoscopic viewer. See photogeology.