Sergei Mikhailovich Prokudin-Gorskii (or Gorsky) (1863-1944) was a Russian photographer that offers a vivid visual portrait of the Russian Empire at its height, and more importantly, the architecture, the scenery and the people of the lands that constituted this empire, including the Caucasus region, and Central Asia.

His pictures include a wide array of interesting topics ranging from ancient Central Asian cities such as Bukhara and Samarkand, to interesting people such as the Emir of Bukhara, Imam Shamil's people, to interesting monuments such as mosques, madrasas, Gur-e-Emir (the Mausoleum of Tamerlane, or Timur Leng), to interesting ethnicities such as Kazakh nomads, Jewish children with teacher, Daghestani tribesmen, and much more. This is a great historical snapshot of the ethnic and cultural landscape in the early 20th century of the Russian empire.

Technologically, his photos were taken using a new technique called Digichromatography. Simply stated, each photo was taken in black and white, but in quick succession, using three filters, red, green, and blue. Then a projector was used to view the pictures using the same three colored filters.

• The Library of the Congress has an extensive exhibit called The Empire that was Russia - The Prokudin-Gorskii Photographic Record Recreated and Photographer to the Tzar: Sergei Mikhailovich Prokudin-Gorskii.
• A Russian site in memory of Prokudin-Gorskii his entire gallery of some 1902 images can be seen here, albeit in low resolution.
• Frank Dellaert has enhanced the photographs digitally using a MATLAB program he wrote, and a technique called 'mosaicking' and the entire photographic record of what is now present of Prokudin-Gorskii work can be viewed on his web site. This contains the entire 1902 images.
• Addison Godel's web site on Prokudin-Gorskii has many useful descriptions in the gallery section, both by himself or by others.
• E. A. Farris also has a gallery of the pictures.
• Another subset of the collection, but in good resolution.
• Alex Gridenko has a list of images on his site: Digichromatography: Restoring Prokudin-Gorskii's photographs. He also sells prints of them.