So he sidestepped that problem: why not just take 3 images, thru filters, on film for each primary colour?
(L: Staraya Ladoga Church, R: Ural Railway Administration Building in Perm).
Remember that image of Mohammed Alim Khan above, & how the colours didn't *quite* overlap in places, & there was visible banding at the top & bottom? Well:
- Suzdal along the Kamenka river, 1912
- General view of Perm, 1910
- Italian woman outside villa, year unknown (possibly an early picture?)
- Jewish children with teacher in Samarkand, 1912(?)
And a supplementary thread I *highly* recommend reading here: