CHROMOGRAF - (Karol Drac)
Innovatory camera for taking pictures in color, designed by Engr. Karol Juliusz Drac.
Camera design of Engr. Karol Drac was based on Young-Helmholtz trichromatic theory of color vision.
According to theory there are three different types of cone cells in retina. Each of them is sensitive to a particular range of visible light: blue, green and red. Brain determines colors by comparing the different signals each cone senses – information of the color is a base sum of information from each individual receptor (RGB color model)
– taken from: http://historiasztuki.com.pl/NOWA/30-00-01-KOLOR.php
Camera for "taking pictures in color" - called by the constructor CHROMOGRAF - was equipped with three prisms placed in the frontal part of the camera.
Drawing attached to the patent documentation.
Thanks to the prisms, camera was capable of taking three photos simultaneously (on three panchromatic plates) - during even and simultaneous exposure equal to 1/15 sec.
Drawing of camera design found in patent documentation.
The positive is obtained from triple negatives, and it was possible to place it in Chromograf to display these images in color.
On 18 April, 1906, at a special meeting of the Photographic Society of Warsaw Drac presented the audience his camera demonstrating color images on the screen.
Karol Drac’s camera was patented in Russia, Germany and the USA.