HISTORY OF PHOTOGRAPHY portrait of an unknown man wearing a black bag; a box of Eastman film plates in his hands and a plate-carrying case for a large format camera. It appears bizarre; but it is an explanatory image on the use of the accessory that allows the sensitive plates to be loaded or unloaded in full light. On the front there is a small window; in celluloid or red glass; which allows to distinguish enough to carry out the maneuver inside the black bag without "burning" the orthochromatic film. Photography; 20th century