The integrated intensity of the diffracted beams present on microdiffraction precession patterns can be used to infer the 'ideal' symmetry, i.e. the symmetry which takes into account both the position and the intensity of the diffracted beams on a diffraction pattern. It is shown that this symmetry is connected with the 11 Laue classes on conventional electron precession patterns and with the centro- and non-centrosymmetrical point groups on unconventional precession patterns obtained without 'descan'.