Early cameras were cumbersome, costly, and often required specialist knowledge of the devices and developing chemicals to use them correctly. Early film development processes, like tintypes and daguerreotypes, relied on potentially dangerous chemical interactions that were best handled in a controlled environment. For daguerreotype images, popular between 1840 and 1860, the photographer put a sheet of copper, coated with silver and exposed to iodine vapor, into the camera. Once the sheet was exposed to light during the taking of the picture, the photographer used a mercury vapor to bring out the image, and then set it with salt.
Because the film process used highly toxic and often dangerous chemicals, photographs were almost exclusively taken by professionals until the twentieth century. Most permanent photography studios were located in major cities, but photographers with out-of-town clients would haul their equipment outside city limits in horse-drawn wagons. This equipment was more than just a camera, which itself was often a large, accordioned box with a lens on one end, plus the glass or copper plates used to take the image. Photographers had to bring along the darkroom and developing chemicals as well.
Early cameras also had a very slow shutter speed, meaning that the shutter remained open exposing the plate to light for a longer period of time. Though early daguerreotype images required an exposure of around twenty minutes, by the early 1840s it had been reduced to about twenty seconds. Even so, photography subjects needed to remain completely still for long periods of time for the image to come out crisp and not blurred by their movement. Sometimes squirming children were put into restraints for the duration of the photo shoot. This need for stillness made posing for a picture a serious business, so the practice of smiling for the camera did not become standard until the 1920s, when technological advancements in camera production allowed for shortened exposure times.