Photo Scale. Photo scale, or representative fraction (RF), is the ratio of the distance measured on the photograph to the distance measured at the ground datum. Photo scale can also be defined as the ratio of the focal length of the camera to the height of the lens above the ground datum at the moment of exposure.
From: Society for Range Management. 1998. Glossary of terms used in range management, fourth edition. Edited by the Glossary Update Task Group, Thomas E. Bedell, Chairman. Used with permission.
