This extends the information in the NSA PDF files created by T. K. Treadwell, William C. Darrah, Wolfgang Sell and numerous other collaborators. This project uses data from these files and additional data from Luminous-Lint to push forward our understanding of where the businesses of stereo photographers were physically based. This is a non-trivial task as countries and their boundaries have changed over time. The names of regions, cities, towns and villages have not been as fixed as one would hope. In these listings variants are provided. Standardisation has been carried out where it does not create confusion.
 
Some countries, such as Poland, did not exist for parts of the nineteenth century placing Warsaw as a part of Russia. The Ottoman Empire controlled large parts of the Balkans as well as most of the Near East and Middle East. St. Petersburg became Petrograd (1914-1924), Leningrad (1924-1991) changing back to St. Petersburg in 1991. Regions such as Alsace-Lorraine have been under the control of different countries over time. Burma is now Myanmar and Ceylon is Sri Lanka. The locational indexes in this project use current nomenclature and additional historic geographical names are provided to clarify specific issues.
 
Indexes to the stereo photographers in individual cities and towns can be provided as required.
 
The lack of the name of a photographer in a country DOES NOT mean that stereographs do not exist as numerous photographers traveled to, but were not based in, these countries. For example Frank Mason Good was based in London, Phoenix Green and Hartley Witney all in England but is remembered for his "Eastern Series" that were taken in Egypt and the Middle East.
 
Vast numbers of additions and improvements have been made to these data sets. Suggestions and corrections are always welcome.
 
Alan Griffiths