A crystal monochromator with a logarithmic‐spiral curvature has been designed as part of a low‐angle x‐ray diffraction camera that uses synchrotron radiation emanating from the storage ring SPEAR at Stanford Linear Accelerator Center. The logarithmic‐spiral curvature allows a greater demagnification of the source than is permitted by a cylindrical geometry. Independent bending couples are applied at both ends of a rectangular crystal plate via pairs of parallel rods which rotate under a linear push from differential micrometer screws. Stepping motors control the bending mechanism, theta motion, guard slits, and camera alignment. A tenfold demagnification of the source is readily obtained. Focusing is rapid and easy. The crystal monochromator is combined with a focusing mirror in order to eliminate harmonics and produce a point focus (Webb, Samson, Stroud, Gamble, and Baldeschwieler, 1975).