Cameras History

A camera is literally a device (analog or digital) used to capture images. These images may be still (photograph) or moving (videos). The term CAMERA was derived from the camera obscura (dark chamber, latin) which was an early mechanism for projecting images. The modern cameras were manufactured from the concept of camera obscura.
Camreas not only work with the light of visible spectrum but also the protions of electromagnetic spectrum. Generally, it consists of an enclosed hollow, an opening (called an aperture) at one end for light to enter. On the other end, there is a viewing surface for the light to enter. Most old fashioned cameras used photographic films and papers while modern electronic cameras use digital chips and papers.
A typical still camera once capture a images the time you press the shutter button.The camera obscura was a darkened chamber or a box into which the light was allowed to pass through a convex lens. The images were fromed on the surface of paper, ice, glass, etc. The camera obscura was first described by an arabian scientist Ibn al-Haytham (Alhazen) in his Book of Optics (1015–1021). English scientist Robert Boyle and his assistant Robert Hooke developed a portable camera obscura in the 1660s.
The first camera obscura was small and portable enough to practical use built by Johann Zahn in 1685. At that time, there was no any reliable way to preserve the images captured by these cameras but manually tracing them. In compensation to that, Johann Heinrich Schultz discovered a silver and chalk mixture darkening against the exposure to light. Before the exposure, a sensitive plate would be placed in front of a viewing screen to capture the image.