PATENT TALK

PATENT TALK

A. Method for Color Cinematography- US 1359024[1] dated 16 November 1920

This particular invention was patented in the year 1920 when most of the film industries were producing films in Black and White. There was a necessity to invent a method to produce movies in color. The patent was filed on 27 December 1919 by Brewster Percy Douglas, an American inventor.

At that time color movies were produced using the following method as cited by the inventor as a prior art[2].

“Series of images or pictures on one of the films taken through a red filter and the other series on the other film taken through a green filter; and then by contact to print the two series on the opposite sides of a positive film which is sensitized on both sides. The positive film is then developed and fixed, and the images on the two sides are stained or colored, say red on one side and green on the other, so that when the two images are projected (of course simultaneously) on the screen a unitary image in substantially natural colors will result.”

The inventor further identified the problem in the prior art and describes the same as follows[3]:

“So far as I am aware this method, in which the color records are made on two separate films has never been successful in practice, however attractive in theory; the reason being the difficulty, insuperable, of securing accurate enough registry of the images in printing them on the positive film. The necessity for accurate registry will be apparent when it is remembered that if the pictures are out of registry on the positive film the defect, greatly magnified, is evidenced on the screen by red and green color bands or fringes at the edges of the objects photographed.”

Further he describes his invention which is an improved method of color cinematography as follows[4]:

“In carrying out the invention in the preferred manner a pair of light images of the object to be photographed are projected to separate focal plane areas; two perforated negative films are passed step by step through the respective focal plane areas to bring the successive image or picture spaces to the exposure positions and the films are so positioned that at least one selected perforation in each film is in a certain definite and exact relation to the respective light image, this relation being constant through out the series of steps; and the films are exposed to the light images while in such positions. Then the negative images produced on one film have with respect to.

Opposite sides of the positive film, if the perforations in the latter are registered with the perforations in the two negative films, the resulting positive images will be in accurate registry, and when projected will produce a single or unitary image on the screen. The positioning of the negative films in their respective focal plane areas is effected by the use of registry pins, which enter the selected perforations, say one on each side of the film, before the exposure is made, so that if a picture-space on the film has at any step been brought to only an approximately correct exposure position the pins will shift the film in one or more directions, in its own plane, to bring the picture-space exactly to the exposure position.

Usually the same perforations as were used to locate the negative images are then used to register the negative images with negative film.”

The inventor highlights the following as the spirit of his invention.

¥ He used two lenses, one for each film, instead of a single lens.

¥ Two exposures (to make an image pair or group) may be made one after the other instead of simultaneously.

¥ In place of exposing two negative films a single film of double width may be used and the images made side by side, After exposure the negative can be split lengthwise to form two separated color records, if desired, or its images can be printed on the two sides of the positive without splitting the negative in two.

¥ For three-color cinematography three separate negative films may be used.

Brewster was a series inventor in the cinematography field. He was granted many patents both in USA and abroad. Brewster was the first to shoot a color photograph of President Wilson[5]. The color cinematography produced by using his inventions is popularly known as Brewster Color. The one-shot Debut of Thomas Cat (general release Feb. 20, 1920) was for many years regarded as the first color cartoon to have been widely distributed[6]. The film was processed by Brewster Color.

[1]http://pdfpiw.uspto.gov/.piw?docid=01359024&SectionNum=3&IDKey=8C9E15FCAC2C&HomeUrl=http://patft.uspto.gov/netacgi/nph-Parser?Sect2=PTO1%2526Sect2=HITOFF%2526p=1%2526u=/netahtml/PTO/search-bool.html%2526r=1%2526f=G%2526l=50%2526d=PALL%2526S1=1359024.PN.%2526OS=PN/1359024%2526RS=PN/1359024

[2] US Patent No.1359024

[3] US Patent No.1359024

[4] US Patent No.1359024

[5] http://brayanimation.weebly.com/other-series.html

[6] http://brayanimation.weebly.com/other-series.html