Seeing the last days of the Russian Empire in full color is nothing short of a miracle considering the technology available in the decade of 1900. However, Sergey Prokudin-Gorsky wasn't the only one experimenting with early color photograph techniques. While not that common, other color photographs did exist in the early 20th century in different formats. Apart from Prokudin-Gorsky, one other man honoured for his early color photographs is Albert Kahn, who did not limit himself to only one country but sought to record the entire world in the early 20th century in full color.
Albert Kahn was actually a banker, and seldom, if ever, went behind the lens of the camera. His name however is venerated in the world of early photography for his patronage and zeal towards recording the world in color.
In the early years of the the 20th century, Kahn had acquired enough wealth through his banking career that he was able to pursue his vision of founding an institution geared towards the accumulation and documentation of knowledge and culture, especially that of other countries. To this end, he commissioned countless photographers to go around the world and record over 50 nations in color.
In order to record the world in color as accurately as possible, Kahn employed Autochrome Lumière cameras. In Autochrome Lumière (simply known as Autochrome), colors aren't recorded in separate frames as in Prokudin-Gorsky's method. Instead, the glass plate (used to record the scene) is coated with a special blend made from starch. This starch contained tiny pigments of red-orange, green and blue-violet. These pigments become the base for building the entire image with color.
Drawbacks to the technique (aside from the expense) include the manifestation of tiny colored dots in scenes with large monochromatic areas (such as images with large areas of sky or sea). These spots are easier to spot when the Autochrome image is held closer to the viewer, and is akin to the digital noise that appears in modern photographs taken with high ISO settings. Autochrome plates also required longer exposures due to the added filters in the camera which blocked certain color wavelengths of light that might interfere with the rendering of the picture's colors accurately.
Albert Kahn's photographers reached almost all corners of the known world at that time. From Europe to North America to East Asia, Kahn's zeal to see the world through colo pictures made it possible for modern viewers to see the world of their great-grandparents and great-great-granduncles and aunts.
Over 72,000 Autochromes have survived in Kahn's collection, and only a fraction of those digitized. As amazing as these few digitized images are, it is still possible then to see even more amazing images still hidden away in the Kahn archive.
The official Albert Kahn website is here. More images depicting the beginnings of color photography can be found on this BBC website. If you wish to explore more early color photographs, there's a book called The Dawn of the Color Photograph: Albert Kahn's Archives of the Planet and a documentary, Wonderful World of Albert Kahn: Archives of Planet as well.