Photo Engineer
Subscriber
Is this to say that the color negative film is passed under a blue light after it is coated and before it is cut and spooled?
And why was it possible to make the curves of the dyes line up properly for color reversal films, but not color negative?
(Not questioning the need for the mask by any means, just want to know how the chemistry and molecular physics differed)
The image forming couplers are actually dyes when coated. When exposed and developed, everywhere there is image, these dyes change color say from red to magenta in a negative representation of the image, and everywhere they do not change there is a positive dye image. These images align exactly because one forms the other! The orange color of the mask is there from the start, but until processed it is uniform.
No light is involved.
Color positive films cannot be masked as they must be viewed in their image colors with a clear white - no mask. Therefore, unless enough measures are taken in processing, the colors are incorrect when compared with color negative. Therefore, these curves line up, but are not correct. The designers of the film and process thus make the film higher in contrast to give bright saturated dyes.
PE