The first permanent photograph was made in 1826 by Joseph Niepce. Together with Louis Daguerre they further refined the process. The process involved silver-coated copper plates mixed with iodine to create a layer of silver iodine. After being exposed to light for several minutes the plate was exposed to mercury vapor and heated to 75 degrees Celsius. Though the prints that these created were not reproducible they were still amazingly popular. These pictures were known as daguerrotypes, and took several minutes of exposure. In fact when taking portraits subjects had to remain still for several minutes. And pictures of scenery often didn’t show people because they moved to fast to be caught by the slow exposure. In 1839 the French Academy of Sciences announced this process.
For more information, see the Engineering Pathway’s resources on photographic processes. For related educational resources, visit the Chemical Engineering Education, and the Materials Engineering Education disciplinary communities.