Technique for Berg-Barrett stereo topography

A stereo pair of Berg-Barrett topographs of an (0001) surface of zinc is obtained with a single exposure. One topograph is the 013 reflection while the other is the 103 and an 84° stereo separation angle results. Errors due to dislocation displacements which might occur between two successive topographs are eliminated, and correction for geometric image distortions is not required.