A daguerreotype begins with a copper sheet that is plated with silver. The plate is polished into a mirror finish and later coated with vaporized iodine inside a fuming box. The iodine reacts with the silver to make the plate light-sensitive, after which it is ready to be loaded into the camera.
Daguerreotypes require exposure times ranging from a few seconds to several minutes. While this is obviously long by today’s standards, it was one of the main advances when the process was publicly introduced in 1839.
The image was made visible by developing the plate with mercury. Inside what’s called a mercury pot, a small amount of the metal is heated up and vaporized. When the vapor contacts the plate, the electrical charge it carries with it activates the silver iodine crystals, revealing the photograph. The image is then preserved by fixing it with gold chloride.
Danh converted a light utility van (which he christened Louis) into a darkroom where he can create and develop the plates. It allows him to work on-site as he travels the country. As daguerreotypes cannot be directly reproduced, they must be rephotographed or scanned in order to be copied. Danh has found that the process of digitizing the plates reveals more detail than what the naked eye could see in the original. You can check out a collection of his daguerreotypes from Yosemite on his website.
Today, taking a photograph is so incredibly simple that it’s easy to forget it wasn’t always that way. While few people are likely to ever attempt the daguerreotype process, perhaps you’ll pause a moment the next time you pull out your phone to snap a quick pic of that epic sunset to remember how far photography has come. From silver to silicon, it is an art that has always pushed the boundaries of science. It’s easy to take it for granted today, but perhaps that’s the most impressive thing of all.