Sergei_Mikhailovich_Prokudin-Gorskii
Prokudin-Gorsky’s own research yielded patents for producing colour film slides and for projecting colour motion pictures. His process used a camera that took a series of three monochrome pictures in sequence, each through a different-coloured filter. By projecting all three monochrome pictures using correctly coloured light, it was possible to reconstruct the original colour scene. Any stray movement within the camera’s field of view showed up in the prints as multiple “ghosted” images, since the red, green and blue images were taken of the subject at slightly different times.
The exposure time of the frames is likely to have varied, even if the developed negatives were later on similar glass plates. In a letter to Leo Tolstoy requesting a photo session, Prokudin-Gorsky described each photo as taking one to three seconds, but, when recollecting his time with Tolstoy, he described a six-second exposure on a sunny day.[11][7] Blaise Agüera y Arcas estimated the exposure of a 1909 photo taken in broad daylight to have had combined exposures of over a minute, using the movement of the moon as comparison.[12]
Though colour prints of the photos were difficult to make at the time and slide show lectures consumed much of the time he used to demonstrate his work, his studio worked in publishing prints of the photos in journals, books, postcards and large photogravures.[4] Many of the original prints from his publishing studio have survived to this day.[13]