What is the process of French lithograph printer Nieps exploring photography?

1793, Nieps, a French lithograph printer, tried to create an automatic transfer method to transfer line drawings to slate. 1826, he coated the asphalt liquid on the metal plate and put it in a black box. After eight hours of exposure, he finally got a rough image. Niepce called this method "daylight photography". Although he has never found a practical photographic method, it is the first permanently preserved photographic image in the world.

This image is now kept in the University of Texas. Daguerre is a French stage artist. He once invented the "peep show", and he is interested in how to keep the images in a black box. He signed a contract with Nieps to study the technology that can better record and save images. But until Niepce died in 1833, there was no obvious new achievement.