This section is from the book "Complete Self-Instructing Library Of Practical Photography", by J. B. Schriever. Also available from Amazon: Complete Self-Instructing Library Of Practical Photography.
605. With this machine, modeling and concentration are secured by the placing of the machine, it being adjustable to any angle from 45° up to a perpendicular line. Any character of lighting can be secured by placing the machine so as to throw the light from the same direction you would secure daylight, and using the reflector at almost right angles from the face of the diffusing frame of the machine. After a few experiments in the production of lighting and the test of different size cartridges with the speed of the lens used, it readily becomes a factorial system of working and must be the same at all times and at all places. See Illustration (No. 86) of machine in use.
606. The cartridge system makes the automatic principle possible, by the use of four cells or magazines which hold ten cartridges each. Four sizes can be carried at once and forty exposures made without reloading. Battery system or direct incandescent electrical current can be used. If working in the studio, use current; if called upon to go out and do work, the battery system can be employed. There is nothing to get out of order, except at long periods the renewal of batteries at small cost.
607. The cartridges are made in eight sizes designated as No. Ox to No. 8x, which will contain from 3 to 40 grains of powder, No. Ox to be used for half cabinet bust and three-quarter length, No. lx for 5 x 7 plates, No. 2x for 5 x 7 group and 8 x 10 bust and three-quarter length, etc.
When lenses are used with a working speed of f. 4.5 to f. 5.5 these factors are correct. When groups are made and the machine is at a greater distance from the subject, the angle of front should be raised to about 75 to 80 degrees and a larger cartridge used.
608. The smokeless feature, by which the machine consumes its own smoke, makes it perfectly clean. It can be used in the most elegant home without dirt or dust. With the extra hood, which is made with larger front, and with the use of larger cartridges, the machine is perfect for dinner parties, wedding groups, etc., at home. For large work or larger negatives of children it can be used in connection with daylight, using the same principles as when using at night, or by reversing the lighting, holding key of light on high-light side to within the tone of the flesh, the machine being placed on the opposite side when flash is made. This system renders soft beautiful daylight shadows, therefore, no reflector is necessary. The simplicity of work and remarkable quality of this machine over all others can only be appreciated after using it.
609. When it becomes necessary to reduce the smoke in the hood revolve the crank (or handle) at rear of lamp; the time required to reduce the smoke will depend on the number of cartridges that has been exploded and the interval of time between explosions. The operator will soon learn the efficient use of the smoke reducer.
For Art Portraiture, Studio System, and index for this volume see Volume VIII.