Abstract
This paper discusses the expected accuracy of the 3D measurement by using a pair of convergent stereo photographs. The only assumption in the discussion is that the optical axes of both the left and right cameras lie on the same plane. The theoretical accuracy of the object-space coordinates of a point is obtained from the measurement accuracy of a point position on a photograph by using the rules of error propagation. The general formulas expressing the root mean square error of the object-space coordinates of a point include the object-space coordinates of the point. The approximate formulas for the normal case and convergent stereo photographs shown in some literatures on photogrammetry are derived from the obtained general formulas.
