A new multiple‐scanning‐slit or scanning‐grid scatter‐reduction geometry consisting of coaxial rotating aperture (RA) cones is described and compared with other RA assemblies such as the rotating aperture wheel (RAW) device. A unique feature of the new design is that the geometric and rotational axes of the conical RA surfaces coincide and are collinear with the x‐ray focal spot. This arrangement of axes should provide the potential for greatly improved mechanical rigidity, higher rotational velocities, and the capability for static slit‐pattern alignment. The common rotational axis of the cone assembly is angled obliquely to the central x‐ray beam such that the intersections of the irradiated portion of the RA surfaces with the plane formed by the x‐ray central beam and cone axes are straight lines parallel to the film plane. This geometry is compatible with the standard source‐patient‐image‐receptor radiographic relationship and allows for variable source‐to‐image‐receptor distance.