GB390327A - Improved process of colour photography - Google Patents

Abstract

390,327. Colour photography and kinematography. I. G. FARBENINDUSTRIE AKT.-GES., Frankfort-on.Main, Germany. April 15, 1932, No. 10860. Convention date, April 15, 1931. [Classes 97 (i) and 98 (ii).] Three-colour photographs or kinematograph films are produced by a combination of additive and subtractive methods by dividing the lightbeam from the object into two beams by any known optical means, passing these beams through filters one of which transmits two of the component colours and the other the remaining one, and causing them to fall side by side on two superimposed sensitive layers so that two colour-record images are formed in superimposition, one on each layer, under the first filter, and the third colour-record image is formed under the second filter in one layer only; developing the records and printing them, preferably on stock coated on both sides, so that the positive components are arranged similarly to the negatives, colouring the superimposed pair in their complementary colours while leaving the adjacent third component uncoloured, and projecting the positive on to a screen by means of the optical system and filters used in the taking camera. A modification is described in which four colour-component images are recorded in superimposed pairs side by side by using filters each of which transmits two component colours. The invention is illustrated for three-colour work, the taking filters Y, B, Fig. 1, being yellow and blue, and the superimposed sensitive layers being blue-green sensitive and red sensitive, arranged in contact with supports outermost. Green and red colour-record images g, rare .thereby formed in superimposition, with a blue record image b adjacent to them, the second layer remaining unexposed in the area u under the blue record. Prints are produced in corresponding positions, Fig. 2, on stock coated on opposite sides. The pair p and by from the green and red records are coloured purple and blue-green respectively, while that bw from the blue record remains uncoloured. The area c under the print bw is blank and transparent. The coloured picture is projected by the same optical system and filters as were used for taking the negatives. When the four-colour process is worked, the fourth record occupies the part u or c of the superimposed sensitive layers (negative or positive) which is unexposed in the three-colour process.