Tuesday, September 19, 2017
Camera Obscura and Hat Camera -- September 19, 2017
A camera which will make the picture bright without blurring it may be made by using a glass lens (See Lenses, Experiments With). These experiments show how a lens will throw a picture, and the picture can be seen to better advantage if the lens be fixed in a hole in the side of a box. The observer may work at the picture through a hole in the top of the box, or the back of the box may be made of thin white paper, so that the picture will show on the other side. There is a certain distance from the lens for every object, where its image will be plainest, so it is a good plan to make the back of the box so that it can be slid in and out. Find the distance at which the lens makes the plainest picture of near objects before choosing the box, and then select one of the right depth. Remove the back, and saw off the edges so that it can be made to slip in as far as desired. Nail a stick to it to serve as a handle by which it may be pulled in and out.
Hat Camera. A camera can be made also from a stiff felt or silk hat, if it have a ventilating hole in the top of the crown. If there are more than one of these holes, all but the central one may be stopped with paper. A piece of thin paper is then pinned over the bottom of the hat, which is held with the top toward the part of the landscape to be observed. A black shawl is thrown over the hat and the observer's head, but care must be taken that it does not hang over the ventilating hole.