Abstract: A diffusion filter can be formed by sandblasting a transparent plate to produce a pitted surface. A neutral density cement having an index of refraction different from that of the plate is applied to the pitted surface and a second plate is then bonded to the first by the cement. The opposing surface of the second plate may also be pitted to achieve increased diffusion. Light that strikes the filter and passes directly through without entering the pits forms a sharp image, while light that enters the pits is refracted so that it forms a soft image superimposed on the sharp image. Some light that enters the pits and is scattered within the cement is absorbed.