A photograph produced by monochromatic X-irradiation of a sample of microcrystalline powder placed at the centre of a circular camera, e.g. a Debye-Scherrer camera. Diffracted X-rays are recorded on a strip of film wrapped around the circumference of the camera. The angular position of the diffracted X-rays on the film gives structural information about the sample. See also x-ray diffraction crystallography.