Did you Know: Galileo discovered the sun spots
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  • Pinhole Camera

    Posted on February 7th, 2012 rudrarup No comments

    How does a camera change a big scene into a small picture? To see for yourself, make a pinhole “camera.” Start with an empty cardboard box. Punch a hole in the center of the bottom by pushing a pencil through it.

    Now place a piece of waxed paper over the open end of the box and hold it there with tape or a rubber band. Your pinhole camera is complete.

    Sit in a dim room that has a bright object in it, such as a lamp or a window that lets in daylight. Lay a blanket over your head and the pinhole camera.

    Hold the camera at arm’s length, with the waxed paper toward you and the punched-out hole sticking out from under the blanket. Point the camera at the bright object. On the surface of the waxed paper, you will see a picture of the object—backward and upside down.

    A real camera uses the same principle as your pinhole camera except that a real one does the job better. A real camera holds a piece of film instead of waxed paper. That film is coated with chemicals that are changed by light. They make the image into a lasting picture.

    In a real camera, the lens does the same kind of job as the little hole—it forms a backward, upside-down image. But the lens lets in a lot more light so the film can do its work quickly.

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