When set up for work be sure to have the tripod top level, which may easily be done by adjusting the legs to the inequalities of the ground.
The Camera is fastened to the tripod top by a thumb-screw, which passes up from beneath, through the tripod top, and into the leg of the box. When adjusted tighten the screw firmly. p164
THE INSTANTANEOUS SHUTTER.
The rapid dry plate and the quick acting lens have created a necessity for a shutter that would make an instantaneous exposure, in order that sharp pictures might be made of objects in motion.
This has been accomplished in a variety of forms, the earliest and simplest of which is
THE DROP SHUTTER,
which consists of two pieces of wood, each having a hole cut into it, and so arranged that when one piece is placed upon the end or hood of the lens (which fits into the circular opening), the other piece can be made to slide up and down against it, thus for an instant bringing the two openings opposite, and making the exposure depend upon the rapidity with which one opening passes the other.
Fig. 1 represents the common form, in which the release is made by the withdrawal of a metal catch, which fits the indent in the side of the sliding upright piece. Fig. 2 represents an improved form, in which the release is made by pressing a rubber bulb connected with a rubber tube attached to a metal valve.
The action of both these styles of drop shutter may be hastened by using rubber p165 bands to quicken the fall of the sliding piece, as represented in Fig. 2 by A and B. So that while a rapid exposure might be made by the fall of the slide, by its own weight, it would not be quick enough for an object moving across the plane of focus, but might be sufficient for an object moving away from or toward the lens. By the use of the rubber bands the exposure may be made as quick as a flash, or the small fraction of a second, thus enabling one to secure a sharp impression of the trotting horse, the railroad train, the racing yacht, and many other interesting and difficult subjects.