Royalty, Espionage, and Erotica: Secrets of the World's Tiniest Photographs
Almost as soon as photography was invented, the first microphotographs followed -to demonstrate the power of a microscope. These tiny pictures became popular among the general public when the Stanhope lens, a tiny magnif...
https://www.neatorama.com/2014/12/03/Royalty-Espionage-and-Erotica-Secrets-of-the-Worlds-Tiniest-Photographs/
