The history of three-color photography (1925)

Record Details:

Something wrong or inaccurate about this page? Let us Know!

Thanks for helping us continually improve the quality of the Lantern search engine for all of our users! We have millions of scanned pages, so user reports are incredibly helpful for us to identify places where we can improve and update the metadata.

Please describe the issue below, and click "Submit" to send your comments to our team! If you'd prefer, you can also send us an email to mhdl@commarts.wisc.edu with your comments.




We use Optical Character Recognition (OCR) during our scanning and processing workflow to make the content of each page searchable. You can view the automatically generated text below as well as copy and paste individual pieces of text to quote in your own work.

Text recognition is never 100% accurate. Many parts of the scanned page may not be reflected in the OCR text output, including: images, page layout, certain fonts or handwriting.

646 History of Three-Color Photography pages of the book are projected through the lens and are properly cast upon the respective sensitized surfaces by the aid of mirrors or other suitable means for bending or directing the light rays. By using a single lens for the exposure of the two sensitized surfaces, not only is the construction and operation of the apparatus simplified, but more uniform results are obtainable." Fig. 181. Brewster's U.S.P. 1,233,176. Again in a later patent33 it is stated: "The apparatus shown in the present instance is adapted to simultaneously expose both sides of a strip of paper or other appropriate material having sensitized surfaces on both sides thereof, the exposure of the two sides of the sensitized medium being effected through the single lens and by the aid of reflectors or equivalent means which divert the light rays from the lens to the opposite sides of the sensitive medium." For printing on double-coated stock Brewster34 devised various types of printers of which one is shown in Fig. 181. The film is fed through 5 in 3; 5 a being the light source and the beam is split up by the device 7, 8, a prism with silvered bars, and thence to the mirrors 9, 10 to the positive film in the film-gate 11. The exposure of the positive film was controlled by rotary shutters 12, 13, one of which is separately shown, with cut-out quadrants. Another type of printer 35 is shown in Fig. 182, in which the negative 20, 20 is illuminated on each side by the lamps 29, 29, 29, 29, and the image is taken up by the prisms 28, 32, and transmitted by the lenses 2, 2, to the prisms 33, 34 and thence to the films 23, 24, 25.