A correction model for variation of distortion within the photographic field

For the attainment of the highest accuracies in close-range industrial photogrammetry it is necessary to account for the variation of radial distortion within the photographic field, especially for large-format lenses. In this paper an empirical correction model is introduced which overcomes serious shortcomings in the traditionally applied geometric correction approach. The new model has been tested with success on a number of medium- and wide-angle, large-format lenses. The results of sample tests are presented, and the effectiveness and practicability of the empirical approach are discussed.