Camera Obscura

• The camera obscura, a box with a pinhole, was an invention exploited by painters to fashion extremely precise drawings as foundations for their paintings. Camera obscura simply means "dark room" in Italian. The light passing from the outside through the pinhole creates an upside down image on the back of the box. By placing a piece of paper or canvas at the back of the box, the artist could trace the drawing of the subject directly onto the paper or canvas. This important optical effect is the foundation of how the camera operates.
  
  

Light-Sensitive Compounds

• Light-sensitive materials with a silver base were discovered in the 1700s. These compounds would change color when hit with light. Later they were developed into emulsions that were placed on glass and, finally, flexible film to record optical information inside the closed box we know as the camera.
  
  

First Cameras

• The earliest photograph of what we recognize today as the camera was in 1814 by Joseph Nicéphore Niépce using a bitumen emulsion. Later the daguerreotype, named after its inventor Jacques Louis Daguerre, used a copper plate covered with a silver solution, creating images first shown to the public in 1839. The camera used for these pictures was essentially a large box to hold the plate.
  
  

Nineteenth Century Development

• By the mid-1800s a more-sophisticated setup was created. A smaller box holding a glass plate covered with emulsion was used, and a stop-action shutter was developed that captured objects in motion. The photographer would operate the camera from behind, under a black tent. In addition to the plate, developing materials were included under the tent, as the photograph had to be developed immediately. These cameras also included glass lenses, that focused the external images more precisely on the plate.
  
  

Modern Camera

• With the principles of iris, lens and light-sensitive emulsions in place, the modern camera is basically an improvement upon prior technologies. Lenses have become fabulously sharp and capable of rendering images from great distances or at high magnification. Flexible films made roll film possible, and as a result cameras became more portable. Chemical advances made it possible to take pictures in increasingly lower light and finally, in color.
  
  

Digital Cameras

• Today's digital cameras are based on the same principles as film cameras, but instead of light-sensitive film they use a light-sensitive digital sensor to record visual information.