654. System To Employ

System To Employ. Every school should be equipped with a photographic dark-room. Many educational institutions have installed a complete system for instruction in photography, and where this is the case photography should, by all means, be employed in the making of records of various experiments. In the event that a school is not provided with photographic conveniences, an individual member of a class, who is interested in photography, may take it upon himself to secure the photographic records. The expense (which will be very slight) may be divided among the individual students, if the school does not appropriate the necessary funds. These photographic records are of immense importance to the individual student, and each member should unhesitatingly avail himself of the opportunity of securing photographs of the various experiments rather than attempt the making of drawings.

655. As previously stated, the average student is not very apt in the art of drawing, and the time consumed in making illustrations by means of the pencil could be far better spent in studying the natural object and the perfecting of apparatus, and in properly performing and arranging the experiments, so that each item would show to best advantage in the photograph. The details and the method to employ will depend very much upon the conditions existing in each school; but the essential features with reference to the photographic apparatus will be the same, no matter whether an individual student takes charge of the work or whether the school itself has its own equipment.

656. The Camera

The Camera. It is not necessary that the outfit be at all expensive, yet the better the apparatus employed the more certain and the more satisfactory are the results bound to be. Much will depend, however, upon the operator, for the knowledge of the methods to employ is of as great a value as the apparatus itself. A camera that will make a picture 4x5 inches in size will answer every purpose, and the expense of using a plate of this size will be very slight. On the other hand, a 5 x 7 picture will give a larger image, and in many cases prove more valuable than the smaller size.

657. In order that different classes of subjects may be adequately reproduced it would be advisable to have a 5 x 7 instrument. Kits may then be inserted in the plate-holders and 4x5 plates used where the 5x7 size is not required. The ground-glass should of course be ruled accordingly; i. e., lines showing the boundary of the 4x5 plate should be drawn so as to come exactly in the same position as the 4x5 plate in the holder. A swing-back or swing-bed will be found a valuable attachment to the camera, for it will be often necessary to tilt the camera, and the perpendicular lines in the subject would be distorted if the plate were not kept parallel to them.

658. Lens

Lens. It is not necessary to have an expensive lens, the main requirement being correction for chromatic aberration and spherical aberration; the lens should also give a perfectly rectilinear reproduction of all lines. The speed of the lens is not an essential factor, for the subjects are all still life, and an exposure of from twenty seconds to a minute or so will not be at all objectionable. An extra rapid rectilinear lens of good focal-length will answer every purpose. In fact, it will be far better to use a lens of this kind if those who are to make the pictures are not thoroughly familiar with lenses of the anastigmat type. The ordinary long-bellows hand-camera fitted with a rectilinear lens will answer every purpose.