A procedure for conveniently determining the orientation of noncubic crystals is presented. The methods usually employed for cubic crystals, flat-film backreflection Laue patterns interpreted with the aid of a table of interplanar angles, is not readily adaptable to noncubics. In general, tables of interplanar angles for noncubics do not exist and if the effort is expended to generate them, such a vast array of angles result that they are virtually impossible to use. It is thus necessary to use the symmetry of the pattern to identify the low-index planes. However, on flat-film geometry, due to the small angular range of the data, insufficient low-index points are present to permit orientation.

In order to alleviate this problem we have developed the necessary techniques for the interpretation of back-reflection Laue patterns employing cylindrical-film geometry. The necessary overlays and their use are presented along with some of the results obtained.