For at least the last seven or eight years, the Prokudin-Gorskii collection of color photos of the Russian empire taken in the early 20th century, gets noticed and reported by journalists, history buffs, and photography enthusiasts. Less well known is that the Turkestan Album, a series of volumes on the people, architecture, history, and economy of Russian Turkestan commissioned by General von Kaufman, the Empire’s first Governor-General in Turkestan, was also digitized by the Library of Congress and made available several years ago. (Many thanks to Fergana News for writing about this, which reminded me that I had a draft post on this from 2007.)
The bulk of the photos in the collection were taken in 1871 and 1872, while some images in the historical volume date back to 1853. The collection contains well over 1,000 photos and is a phenomenal resource not only for a glimpse into Central Asia of the mid- to late-19th century, but also into how the Russian Empire viewed the people of these territories.
(P.S. — Fergana News also recently posted some interesting photos of clay structures in Uzbekistan taken between 1974 and 1989.)