Page:Popular Science Monthly Volume 88.djvu/631

 Popular Science Monthly

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��Making a Kite-Camera

FEW of us can have the experience, at the present time, of a ride in an aeroplane, but it is quite possible to see .Jiow our surroundings look from a high viewpoint, by taking pictures from a kite. It would take a very large kite, indeed, to carry some forms of ready- made camera, but it is easily possible to make a camera light enough so that it can be attached to any good kite and still be capable of making perfect pic- tures.

The lens is probably the most impor- tant part of a camera, and for a kite- camera nothing would serve the pur- pose better than a single achromatic lens, such as is fitted to small box cameras. Such a lens is light in weight and capable of making very good pic- tures. The lens can be bought very reasonably, or one can be taken from some other camera. The lens should be obtained first of all, before starting the construction of the Camera, as the di- mensions of the camera box must be in proportion to the focal length of the lens. A lens of two or three inches equivalent focus is satisfactory. The equivalent focus of the lens can be de- termined by focusing the sun on a piece of paper. The distance of the lens from the paper when the sun is focused to a burning spot is the distance at which the lens is to be placed from the plate or film.

For the purpose of kite photography a camera taking pictures two inches square is big enough. If larger pic-

���The camera used should be built of the lightest materials and every allowance made for air resistance

lures are desired they can be subse- quently enlarged. The construction of the shutter and camera box is explained by the diagrams.

The box of the camera is made cone- shaped in order to reduce the weight and air resistance. The sides of the

��� ��A kite-camera is easily built. It makes _ bird's-eye photographs

camera are made of light but stift' card- board, glued together with a strong ad- hesive. The back of the camera is made in the form of a tight-fitting cover, also made of cardboard, and the inside measurements should be the same as the pictures to be taken. The lens is fitted to an additional partition of heavy card- board fitted inside of the cone, at the same distance from the back of the camera as the focal length of the lens. By sliding the lens back and forth slightly in its tube, a sharp focus can be obtained on distant objects, and the lens is then firmly fixed in position.

The front of the camera, also of card- ])ard, is provided with a circular open- ing which must be large enough so as not to obstruct the view of the lens. On to the front is fitted the shutter, which consists of a sheet of cardboard blackened on the inner side, and cut in a triangle shape. Into the shutter, near the center, is cut a slit, which serves to make the exposure, by admitting light through the lens when it moves across the aperture. The size or width of the slit regulates the time of exposure, and a few trials should be made in order to obtain the most suitable width for the speed of the lens and film to be used. In general, the slit can be as large as it is possible to make it without admitting light to the film while the shutter is

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