Dating old tintypes
, in an upper-story window workroom in Le Gras, Niepce set up his newest invention, his camera-obscure, placing a polished pewter plate coated with bitumen of Judea, a petroleum asphalt derivative, as his chemical of choice to 'burn' an image on different metals.Each experiment took many hours and many days sometimes to develop some kind of image.In place of Niépce, his partner, Louis Jacques Daguerre, an artist, took over the experiments.He changed the name of the image to "Photographie" noting a positive, instead of a negative.The word 'photographie' was also in the Greek language meaning "drawing with light".
Some were lost in the Plains area during travel in covered wagons, some found were without frames as their corners appeared clipped where they clipped onto the frame body inside the brass surround. Made mostly for the high social ranks, Collotypes were actually a handcrafted artistry.
Although Talbot tried to control his patent rights, by the late 1840s, French photographers including Louis-Adolphe Humbert de Molard in Normandy, Louis-Désiré Blanquart-Evrard in Lille, and Gustave Le Gray in Paris were circumventing their potential of the calotype photos. After that, more photographic scientists had found new recipes for the Collotype photos and this type of photo became more popular later in 1918as the Ferrotype waned from popularity in 1917 and plastic film was invented and being used.
The final transition between Ferrotype era and plastic film, was 1934 when it ruled the World.
After at least one day of a long exposure and washing his plate with a mixture of Oil of Lavender and white petroleum, his mixture dissolved some of the bitumen which had not been hardened by light.
The image recorded was from his upstairs window, his lens pointed to the court yard below, that image was faint, as it hardened on a glass plate.