Abstract: A generally planar light-diffusing sheet or screen has, in one embodiment of the invention, off-axis characteristics such that the maximum aligned gain, is at significant angle with respect to the normal to the plane of the sheet or screen. In another embodiment, the maximum gain is at an angle of 0° to 20° to the normal to the plane of the sheet or screen. The screen may be a photopolymer diffuser in which the light diffusive characteristics are due at least partly to refractive index variations within the material of the diffuser, and wherein said refractive index variations define graded refractive index lenses or analogous optical features having optical axes which are inclined with respect to the normal to the plane of such sheet or screen.