Mixing Colors on the Screen 



A new way of obtaining motion pictures in natural colors 

 By Max Fleischer 



Unexposed 

 film 



EVERYBODY knows fhat motion 

 pictures appear to be alive because 

 the eye is not able to tell when one 

 picture is flashed on 

 the screen and anoth- 

 er takes its place. 

 The phenomenon is 

 known as "retinal 

 persistence." In the 

 Kinemacolor process 

 of reproducing scenes 

 by motion picture 

 photography in actu- 

 al colors, retinal per- 

 sistence is relied upon 

 to secure the color 

 effect as well as the 

 effect of motion. In 

 the Kine macolor 

 process an exposure 

 is made to rays that 

 have passed through 

 a blue filter, and then 

 another exposure to 

 rays that have passed 

 through a red filter. 

 Thus, blue and red exposures alternate 

 throughout the entire picture. In order 

 to obtain the effect of natural colors on 

 the screen, it is obvious that the film must 

 be projected at double the usual speed, 

 simply because it has been 

 made in the first place at 

 double the usual speed. 

 As the eye views the pro- 

 jected picture it is bom- 

 barded by red and blue 

 images which succeed each 

 other so rapidly that the 

 colors are combined. A 

 mixture of red and blue is 

 the result. In other words, 

 the screen receives two 

 entirely separate colors in 

 rapid succession and the 

 eye is forced to mix them. 

 Our eyes are fooled be- 

 cause they are slower than 

 the projector. 



This explanation is nec- 

 essary in order to under- 



Film receiving re-' 

 filtered image 



'.flectors". 



Ray-spirtting 

 plane 



Single 

 lens 



-Shutter 

 Reflector' 

 Film receiv- 



stand the basic principle of the new 

 Technicolor process. Here two sets of 

 photographs are also made, not at suc- 

 ceeding intervals, but 

 simultan.eously. 

 These pictures are 

 separated the dis- 

 tance of two pictures 

 on the film, to allow 

 room for double lens- 

 es used in projection. 

 The registration of 

 the colors is accurate, 

 and the eye is not 

 fatigued. 



Double photog- 

 raphy is made possi- 

 ble by an ingenious 

 light-splitting device 

 which is located in 

 back of the lens. The 

 accompanying dia- 

 gram explains the 

 principle clearly. The 

 light-splitting device 

 is nothing more than 

 a prism, the face of which has been 

 coated with silver in numerous squares 

 comprising exactly one-half of the total 

 surface area. The balance of the surface 

 remains transparent. One set of rays is 



Ing blue filt- 

 ered image 



CiaW advances 

 filnn double 

 lenqtn at each 

 exposure. 



Exposed film. 



The motion - picture camera which 

 takes two pictures simultaneously at 

 the usual rate of sixteen per second. 



Red 

 filter 



lilter 



Ray to film 



Camera 

 lenics 



Ray to dim 



How it works. 



«y marks 

 are 

 ctedw;«h 

 the tcenes and 

 Bdjuitedon the 

 screen 



Above: The rays of liRht coming through the 

 lenses are spht into two parts by a novel form 

 of reflector; part of the UkIU passes throUKh 

 a red filler and part through a blue filter. 



To the right: How the blue and red exposures 

 appear on the strip of film for projection. 



First red A and blu« 

 A photographed ani 

 projected 

 uUsneously 



Second red B arid 

 blue B together 



Third redCsr>d blu« 

 C together 



Fourth ted D and 

 blue D to9eth«r 



220 



