Abstract: An X-ray apparatus for transverse axial tomography by direct exposure of a photographic film.A localizer, constituted mainly by a lead-lined cylindrical tube, is fixed to a pivotal lever in the vicinity of the source of X-rays. It contains, in particular, a set of movable filters and movable opaque shutters each of which is moved by driving means according to the movements of the pivotal lever so that the essential part of the beam never impinges directly on the cassette holder and the rays located at the edge of the beam are less powerful than those located in the center region.A transverse tomography apparatus of general utility.