The early twentieth century saw major advancements in the science of photography. By the turn of the century, photography exposure times were almost instant, but the camera equipment was cumbersome and clunky.  In 1913 the ‘candid’ camera was invented by Oskar Barnack and the Ernst Leitz company. It was a much smaller camera than anything that had gone before, and opened up a brave new world for erotica. With the advent of portable photography, photo journalism began to develop. Now, and then, artists photographed the world of the sex worker. artist E. J. Bellocq is best remembered for his candid pictures of sex workers in the Storyville red light district of New Orleans. The mysterious ‘Monsieur X' was an amateur Parisian photographer of the 1920s and 30s who left behind more than five thousand images of Parisian sex workers from the 1920’s.Other photographers of nude women of this period include Alexandre-Jacques Chantron, Jean Agélou, Alfred Cheney Johnston. Chantron was already an established painter before experimenting with photography, and Julian Mandel.