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The Camera

camera1.jpg (3284 bytes)A camera is a device for recording an image on film or some other light-sensitive material as in photography camera. It allows light to enter through a lens or a series of lenses. The light enters the aperture and is "enhanced", and when the light comes into contact with the light, it reacts chemicaly with the chemicals coated on the film. For example, Silver Bromide is decomposed into the components silver and bromide ions when light touches it. Thus, it is an active ingredient for use in film negatives.

The camera consists of a lightproof box, a lens which light enters through and is then focused. The shutter controls the opening size of the lens and the length of time it is open to expose the film inside, and also a viewfinder that shows the photographer the image that the user would see if he would to be in the position the lens would be. The camera developed from the camera obscura (dark room in latin), an artist's tool dating from the Middle Ages. It was a light-tight box with a convex lens at one end and a screen that reflected the image at the other. The artist would then trace the image. The motion picture camera, comes in a variety of sizes, but still , all operates on the same basic principle, light exposure. As the film goes through the camera, it is stopped briefly for about 18th to 24th of a second to expose each frame. A claw pops into holes in the film, and pulls it down , then retracts while the frame is exposed by the light entering , and then repeats this process for the next frame.

This device resembles the eye in many of its mechanisms. What is the significant difference ? The camera permanently records an image on film.

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