The geologic interpretation of aerial photographs is based on the fundamental recognition elements that include shape, size, pattern, shadow, tone or colour, texture, association, and site.
The quantity and quality of geologic information that can be interpreted from aerial photographs is dependent upon the training and experience of the Interpreter in geology and remote sensing.

The three-dimensional view of the terrain reveals important topographic information that cannot be obtained by viewing single photographs.

See for yourself, by gazing at the above photostereopair to see it in 3D.

Although oblique airphotos are often of value to the photogeologist, most studies make use of vertical airphotos.

Most of the photographs used in photogeology are acquired under relatively high solar illumination angles to ensure that ground detail is not hidden by cast shadows. When there is a need to enhance surface irregularities, special purpose photographs are acquired with low sun angle illumination. Whenever feasible, both high and low sun angle photographs are obtained for a given study area.

Medium to large scale airphotos are best suited to the detailed study of a localized area, whereas small scale airphotos, such as those obtained from earth orbit, find their greatest utility for regional surveys.

In photogeology, the convergence of information principle is often employed, whereby an interpreter starts with small-scale photographs for a synoptic view and gradually focuses upon a local or target area by interpreting successively larger scale photographs.

Regardless of scale, however, it is important to remember that ground observations (i.e., field geology) can't be replaced by photogeology.