Patent GB-949764-A (GB)
Title: Mosaic photography
Inventor: SMITH PHILIP STANLEY
IPC: G03B37/04
Filed: 1962-01-18
Abstract: 949,764. Mosaic cinematography. SMITHDIETERICH CORPORATION. Feb. 23, 1962 [Jan. 18, 1962], No. 1878/62. Heading G2E. A method of producing positive motion picture transparencies capable of being used for projecting sections of scenes on to a screen comprises the steps of recording each scene in a plurality of overlapping sections on strips of film corresponding in number to the number of sections (so that each section of the scene is on a separate strip of film and has images recorded thereon which are duplicated on each strip of film containing immediately adjacent sections of the scene) introducing a gradation in the intensity of light reaching the areas on the strips of film containing the duplicated images while so recording the scene on the strips of film and while processing the positive motion picture transparencies from these strips of film, introducing a further gradation in the intensity of light so that this second mentioned gradation in combination with the first mentioned gradation in the intensity of light will cause a graduated darkening of said transparencies towards their edges in the areas of said transparencies containing the duplicated images. In camera apparatus for recording a scene in a plurality of sections, as disclosed in Specification 873,118 and shown diagrammatically in Fig. 1, three cameras A, B and C with strips of film 12,14 and 16 respectively record sections of scene corresponding to angles α, #, γ respectively, light rays from the outer sections being directed to the respective cameras by way of mirrors 18 and 20. Light vanes 22, 24 prevent the side cameras from receiving direct illumination. Transition areas 34, 36 (Fig. 3), in which images are duplicated, are provided on adjacent films, such as 30, 32 and these areas are adjusted to a suitable width by rotating the mirrors 18 and 20 slightly. These areas are overlapped when the pictures are subsequently projected. It is found that the vignetted areas 38, 40 obtained during filming (for example by the vanes 22, 24) in which areas gradations in density occur, are not as wide as the desired transition areas. Accordingly, to avoid obtaining bright lines in the areas of overlap, when projecting, a further gradation in intensity is introduced. This may be done, for example, by a supplementary exposure to light of undeveloped positive film through a suitable mask either before or after the imagewise exposure to the negative. A mask may also be used to provide the second vignette during exposure of the negative film. A suitable mark, with either opaque or transparent central region (according to whether for use with positive or negative film) and varying density margins, is described with reference to Fig. 5 (not shown). Two other arrangements for giving a supplementary exposure to the transition areas of unexposed positive film are illustrated in Figs. 7 and 8 (not shown). In the former arrangement light from a source is directed to the positive film through filters, a rockable lens and a mask with a slit positioned above the transition area of the film.