Photography depends upon the effects of light on various chemicals sensitive to its action.

Some means are required for the proper control of the light, in order that it may be entirely excluded from the sensitive surface, until such a time that, all things being ready, it may be admitted, and then only through a proper channel. The embodiment of these requirements is the camera.

The Camera Stand Hand Folder /FirstStepsInPhotography 5

Fig. 1.

The prototype of all cameras is the Pin-hole Camera, Fig. 1. This shows it in its simplest possible form, consisting merely of a box having at its front end a small hole, A, made by a pin-prick, through which passes the image in the direction indicated by the dotted lines to be received at the opposite end, B, where, if a sensitive plate - suitably screened - is made to take the place of the back portion, the image will be impressed.

This type of camera is not often met with, so the first advance, in which the pin-hole is replaced by a lens, will be considered. This is typified in the Hand camera, Fig. 10.

Cameras are divided into two classes, namely, the "Stand" and the "Hand." The latter is again divided into three sub-classes, the "Magazine" the "Reflex" and the "Folder."

The Camera Stand Hand Folder /FirstStepsInPhotography 6

Fig. 2.