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With your naked eye: Making a pinhole cameraA pinhole camera simply means a camera without a lens. Instead, light passes through a tiny hole in the "camera," forming an image. Pinhole cameras can be just about an size, and can be made out of just about anything you can think of... even out of sea shells. The science behind pinholes can be traced as far back as the fifth century BC and a Chinese philosopher named Mo Ti. Basically, a pinhole camera is a box with a small hole in one end and a piece of film or photographic paper at the other. To make your own version of the pinhole camera, you'll need the following materials: --an empty Pringles potato chip can; --a marker; --an X-Acto or utility knife; --a thumbtack or pushpin; --some masking tape; --aluminum foil; --scissors; and --a bright, sunny day. Construction 1.) Remove the lid from the Pringles can and wipe out any grease from inside. Don't throw the lid away! You'll need it later. 2.) Take your marker and draw a line around the can, about 2 inches up from the bottom. Cut along the line with the scissors. 3.) The shorter of the two pieces should have a metal bottom. Make a hole in the center of the metal with the thumbtack. 4.) The plastic lid will be used as your screen. If your lid is clear, you'll need a piece of wax paper to act as the transluscent screen. Put the plastic lid onto the shorter piece. Put the longer piece back on top. Tape all the pieces together. 5.) To keep light out of the tube, use a piece of aluminum foil that's about 1 foot long. Tape one end of the foil to the tube. Wrap the foil all the way around the tube twice, then tape the loose edge of the foil closed. If you have extra foil at the top, just tuck it neatly inside the tube. 6.) Go outside on a sunny day. Close one eye and hold the tube up to your other eye. You want the inside of the tube to be as dark as possible-so cup your hands around the opening of the tube if you need to. Look around your yard through the tube. The lid makes a screen that shows you upside-down color pictures! 7.) Hold your hand below the tube and move it very slowly upward. Your hand is moving up, but you'll see its shadow move down the screen! The Science How does a hole in the bottom of a Pringles can make a picture of the world? The hole doesn't make the picture. The image of the world is always there. All the hole does is make it possible for you to see it. Suppose you point your Pringles Pinhole at a brightly lit bouquet of flowers. Light reflects off the red rose, the blue iris, the white daisy, and the green leaves. If you hold a piece of white paper near the bouquet, some of that reflected light will shine on the paper-but it won't look like anything. That's because light bouncing off the red rose ends up overlapping with light bouncing off the blue iris, the white daisy, and the green leaves. There are many images of the bouquet on the paper-but they overlap with one another, and the colors all blend together, making a jumble of light. The hole isolates a small part of the light, sorting a single image from the jumble. Only a few of the light rays reflecting off each point on the rose are traveling in a direction that will let them pass through the hole. The same is true for light bouncing off all the other flowers in the bouquet. On the other side of the hole, these light rays reveal an image of the bouquet. That's it! You've made a camera! This kind of camera is called a camera obscura-which is Latin for "dark chamber." The first camera obscuras were small rooms that were completely dark except for a tiny hole in a wall that let in a dot of sunlight. People in the room saw an image of the trees and sky on the wall opposite the hole-and were amazed when the image disappeared at sunset! Thanks to photo.net and exploratorium.edu for the information. 7/28/08 Date: 7/23/08 Advertisement
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