The approximate vertical displacement of faults can be obtained in many cases from a stereoscopic study of vertical airphotos, using one simple measurement involving no parallax measurements. Two methods are used - the first for faults that offset beds having appreciable dip, and the second for faults that displace flatlying beds. In both cases, it is necessary to identify a specific bed on both sides of the fault. Competent interpreters can expect a plus or minus 10% accuracy in the first method, and a plus or minus 20% accuracy in the second. The second method may also be used for estimating the height of cliffs or hills.