Click! Today, a digital camera can capture a scene in less than a second. That was not always so. In the early days of photography, it took up 20 minutes to take a picture. These early photographs, called daguerreotypes (dah-gehr-oh-types), were produced by a process developed by Louis Daguerre who lived in France.
To take a daguerreotype, a photographer placed a silver-plated copper sheet covered with iodine into a camera and exposed it to light. Because material wasn't very sensitive to light, it had to be exposed for a long time. Then the photographer placed the sheet in a cabinet with mercury vapor to develop the image. The fumes from the vapor combined with the silver to produce an image. To stop the developing process, the photographer rinsed the sheet in a salty solution.
Daguerreotypes caught on as more and more people wanted their picture taken. For the first time in history, people could preserve actual images of themselves and their loved ones. Unfortunately, daguerreotypes were very delicate and many of these photographs faded or fell apart over time. By the 1850s, the daguerreotype became less popular as faster and cheaper ways to take photos became available.
Posing for a daguerreotype portrait was time consuming. The process could take as long as 20 minutes. In order to not blur the photo, the person posing couldn't move.