I suppose that all Russian people know Prokudine-Gorski as an official photographer of Nicolas II. Between 1909 and 1916, he collected 3500 views of the Russian empire.
The process used was trichromy. It gives astonishing smooth colours. If you are in Paris these next weeks...
Yes, it was very-very interesting photographer, who has already made colour photos before the official colour photography was born . Unfortunately his collection was for years deponated in the US Congress Library and was "new opened" only at the beginning of 80th.