If a series of pictures, taken from juxtaposed points of view, are projected from a battery of projectors onto a reflecting screen, the projected picture will exhibit relief, provided the screen has certain properties. These properties are (1) that of reflecting the light beams directly back toward the projectors, with no lateral spread, and (2) that of introducing a vertical spread or diffusion. Two types of reflecting screens having these properties are described. One consists of vertical rods, of front and rear curvatures such that the image of the projecting lens formed by the front surface is accurately in focus on the rear surface, which is coated with diffusing material. The second type consists of vertical strips of mirror, standing in pairs at 90° to each other and alternately plane and horizontally ribbed.
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