Weissenberg technique

A technique used to overcome the problem of overlapping reflections in the identification of the symmetry and the dimensions of a unit cell in X-ray crystallography. In this technique, a screen is placed in front of the film allowing only one set of reflections to be exposed. The Weissenberg technique produces distorted photographs, but this can be overcome by having a coupling between the motions of the crystal and the film. Using the precession camera technique undistorted photographs can be obtained.