Colour Photography.

Progress, 1 November 1905, Page 17

Colour Photography.

Readers of the daily newspapers are familiar with the paragraph which periodically appears, informing them that the p/oblem of how to duplicate the colours ot nature by photography has at last been solved. The few, however, who have studied the subject, and know its difficulties, do not easily accept such bare statements, and it may truly be said that the public see little or nothing of its results from such proposed methods. An opportunity of seeing something tangible was, however, recently afforded to visitors to the photographic exhibition lately held under the auspices of the Victorian Amateur Photographic Society. In a lecturette Mr. J. Patterson (of Messrs. Patterson, Shugg & Co.) described a process of photography m natural colours, and demonstrated the success of the method by about a score of examples, which were projected upon the lantern screen by means of the ordinary limelight apparatus. The process by which these slides (which contain m themselves all the colours of the originals), were produced, is based on the wellknown three-colour theory, which shows that white light is really equivalent to a mixture of three colours only, combined together — viz., red, green, and violet ra y S — anc i that all colours whatsoever can be compounded from these three m various proportions. Three negatives are made on colour sensitive plates. The first is taken through a red glass or filter, which allows only the red rays to act ; the second through a green, and the third through a violet filter. By this means is obtained the value or amount of the fundamental colours reflected from the original. Three positives from these are made on gelatine films, which on development are caused to absorb respectively the three complimentary or pigment primary colours — blue, pink, and yellow. The superposition of these three films shows by transmitted light all the colours of the original. The examples shown include a number of natural flower studies, m which the brilliancy and fidelity of colouring were remarkable. Three slides of views in the Botanic Gardens were also wonderfully realistic m their representation of the natural colours. The process amply demonstrates the possibility of duplicating the colours of nature by purely photographic means.