Brewster Colour

Brewster Colour was invented in 1913 by Percy Douglas Brewster

Brewster colour was a two-color subtractive color process introduced in 1915. For the original photography a red and a green separation negative was exposedi in a beam splitter camera. Prints were made on duplized positive film. The process was extensively modified after 1930 and made into a three-color system.

Roderick T Ryan ' Hisrory of Motion Picture Color Technology The Focal Press 1977 p 72-7

Obituary in the SMPTE Journal

Percy D. Brewster died on October 27 at his home at East Orange, N.J., after a longillness. He had retired 12 years ago. His work as a motion picture engineer led him tocredit as the inventor of several color photographic processes, with 360 patents grantedto him. He was President of the Brewster Color Film Corp. of Newark, N.J., and of theformer Revelation Film Corp. of London.He became a member of the Society of Motion Picture Engineers in 1929 and was madea Fellow in 1934. He was cited by the Royal Society of London for his work in colorphotography and was the first to make a color photograph of President Wilson. He wasgraduated from Cornell University in 1906.

SMPTE Journal Volume 59 December 1952 page 546

Brewster had a large number of patents in his name.

Cornwell-Clyne in Colour Cinematography 3rd Edition 1951 page 11 said:  'The bipack method of obtaining two-colour negatives is traceable again to Ducos du Hauron (FP 250,862, 1895) and A Guertner (BP 7924,1903).  One of the first to apply the bipack system to cinematography seems to have been P. D. Brewster (BP 2465, 1915) and (USP 1,222925, 1917).  He was also the first to use registering pins in cameras and projectors (USP 1,359,024, 1920).

There is a considerable amount of information on Brewster’s patents, his printing methods and  his cameras in: History of Color Photography Josesph Friedman 1945 The American Publishing Company, Boston USA. 

Click on the images to see larger images

Note the magenta dye at the top of the image and the mixture of cyan and yellow dye at the bottom.  In the image at the top of the page you can see that the yellow image that was printed by imbibition is slightly out of position

A demonstration of three colour Brewster colour was presented April 12, 1935 to a joint meeting of the colour and kinematograph groups of the Royal Photographic Society. Among of the films presented was ‘Let’s look at London “ a film which showed interior and exterior scenes including a ballet performance. Comments regarding the showing were ‘remarkable steadiness‘, ‘extraordinary good reds’.  It was believed the lack of sharpness was due to imbibition printing.

Roderick T Ryan ' Hisrory of Motion Picture Color Technology The Focal Press 1977 p 72-75

The Photographic Journal of the Royal Photographic Society August 1935 pages 455 and 456 has the full report of the demostration.  There some extracts below.

Here is a section from:

Colour Cinematography 3rd Edition. Adrian Cornwell-Clyne, Chapman and Hall Ltd London 1951 P 411

Printing-Brewster employed double coated positive film printed on one side with a red filter negative and on the other side with a green filter negative.  The development of these was carried to a low gamma and exposure was light. These two images were converted into silver iodide with basic dyes - a process originally invented by A Traube DRP 187289 1905.  The side printed with a red filter negative was dye toned subtractive primary cyan; the side printed with a green filter negative was dye toned subtractive primary magenta. The remaining yellow component was printed on top of the dye toned image by imbibition from a relief matrix film made in the customary manner by developing with a tanning developer such as Pyro or Pyro and adurol.  The unhardened gelatine was dissolved away with hot water after development. Such a method was elaborate and must have been somewhat difficult to control both as to registration and colour balance.

  The following description appeared in 1935.

The red and green negative record records are printed onto two sides of a double-coated positive film.  The images are bleached out to invisible silver iodide images and are toned with basic dyes to pink and blue. The pink side is then coated with another emulsion, which is exposed to the blue negative record and correspondingly tinted by new process which is not being divulged until further patents have been granted. Basic dyes are said to give an advantage over the acidic acid dyes used by Technicolor.

Sic: Adurol: a chlorinated (or brominated) derivative of hydroquinone used as a photographic developer.

This is a photo of Urban's sample and note saying 'Brewster'.

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Some extracts from the Photographic Journal.

The    Camera

The real interest, however, was in the camera, which was patented about 1932. The patent described a beam-splitter inwhich the light from a single lens was divided up inside the camera so that it recorded on three separate films……

… That camera (said Dr. Spencer) was giving quite good service, but the use of the bipacks had several disadvantages, the chief being that the rear image, which was normally the blue printer., was always very slightly woolly, because in front of it was a silver emulsion which was scattering light. … Brewster's suggestion was that the light should be divided up between three separate negatives, each of which should receive light from the whole of the lens. The way in which that was done was to makeuse of metallic mirrors, rather like propellers, disposed at right angles to each other.

The Sound Track.

Some questions were asked with regard to the sound track and it was explained that a fourth printer was not used and so the track had to be either printed in one of the colours or else be a separate silver image.  If they had printed it in all colours so as to get black there would be a risk of the sound going off when the colours ran out of register, so they chose one colour which in most of the shots shown was the magenta