A novel collimator is described which makes use of eight identical plates having holes located randomly. A holder aligns the plates so that on-axis x rays pass through the same hole in each successive plate. Off-axis x rays are attenuated by a factor of T8(=2×10−4), where T is the transmission of a single plate. The angular response measured at 8.34 Å was 15′ wide at half maximum and had wings because of the overlapping of the holes. The design has the advantage that it defines one unique direction rather than several, as is the case when regular hole patterns are used.