Patent GB-591263-A (GB)
Title: Improved process and apparatus for obtaining photographs giving the impression of relief
IPC: G03B35/24
Filed: 1938-07-04
Abstract: 591,263. Stereoscopic and colour photography. RELIEPHOGRAPHIE SOC. POUR L'EXPLOITATION DES PRECEDES PHOTOGRAPHIE EN RELIEF M. BONNET. July 4, 1938, No. 19773. Convention date, July 2, 1937. [Class 98 (ii)] Apparatus for producing photographs giving the impression of relief and, in a modification, colour comprises a plurality of objectives arranged in parallel rows before corresponding rows of photographic plates and equidistant from the axis of optical means which divide the incident beam into a number of beams giving juxtaposed images on the rows of plates which, after development, are replaced in the apparatus and printed by projection on a single plate through a screen comprising opaque areas separated by narrow transparent slots. The objectives 8, Fig. 3, are carried in apertures in walls 2, 3, 4 having partitions 9 and supporting photographic plates 11. The optical dividing means comprises a series of totally reflecting prisms 16, 17 directing beams respectively towards the objectives in walls 2, 3 and between each of which is a block 18 to equalise the light path to the objectives on wall 4. All the surfaces of the prisms and blocks except those by which the light enters and leaves are provided with an opaque black coating. To make an exposure, a slit shutter may be moved in front of the system or the prism blocks may be mounted on a carriage 15, Fig. 6, longitudinally slidable parallel to the rows of objectives a distance corresponding to the width of the field of each objective. Such movement is effected by a hand wheel operating a slotted cam engaging a pin on the carriage 15. After development, the plates 11 are replaced in the apparatus and projection units comprising cases 31, Fig. 6, condensers 32 and tubular lamps 33 are placed in position and the images projected by the objectives on a photographic plate placed in the same position as the original object and before which is an opaque screen carrying a large number of vertical slots. The plate is developed and on being viewed through the slotted. screen gives the impression of relief. For producing relief effects in colour, the apparatus shown in Figs. 9, 10 is employed. The objectives 8 and prism system are arranged as before, but rotatable about the line of intersection of the optic axes of the objectives is a casing 37 divided into compartments by longitudinal portions 39, Fig. 9, and transverse partitions 40, Fig. 10. The compartments are in groups of three, each co-operating with one of the rows of objectives, and each group carrying three colour filters 41 of red-orange, green and blue violet. Panchromatic plates 11 are supported at the ends of the compartments and covers 12 are provided. Exposure is effected by transverse movement of the prism carriage 15, Fig. 10, against action of a spring 35 by means of a lever 46 engaging a cam drum 45 driven from the shaft 43 which carries a pin 42 driving the wheel of a Maltese cross 44 for rotating the casing 37 so that successive rows of filters are registered with the objectives to make an exposure. The Maltese cross is arranged to hold casing 37 still while the carriage 15 makes the necessary exposure movement. When all three rows of plates have been exposed, they are removed, developed and replaced in the apparatus in the same position. The covers 12 are replaced by projection units of the type shown in Fig. 6 and the images are projected successively on to a film of the type known under the Registered Trade Mark " Autochrome " through a slotted screen. After the three groups, each of three colour record negatives, have been projected, the " Autochrome " plate is developed and fixed and then viewed, as before, through the slotted screen when an impression of relief and of colour will be obtained. According to the Specification open to inspection under Sect. 91 the plates may be replaced by a single flexible film. This subject-matter does not appear in the Specification as accepted.