Chapter | 11 |
Photographic camera systems
A camera is essentially a light-tight box with a lens at one end to form an optical image and a fixture to hold light-sensitive material at the other to record this image. Most cameras have some means of focusing the image sharply at the photoplane for subjects at different distances. The duration of exposure to light is controlled by a shutter system, either mechanical or electronic. During the exposure the image illuminance on the film is controlled by an iris diaphragm, the aperture diameter of which can be varied. The optimum settings of the shutter and iris diaphragm are linked to an exposure determination system using light ...