Excerpt from Beginners' Troubles Classes of Cameras. The box cameras have the advantage of always being ready to take a picture by simply making the snap and winding the film until the next number appears at the red window. They do not require focusing. The lenses are single meniscus achromatic and require good strong sun light for successful snapshots with the single speed of snap (about 7513 second) which the shutter will give. There is, in the very cheapest forms, only one opening (usually called stop or diaphragm in front of the lens; but the next larger size has three stops, each smaller Opening requiring double the exposure of the next larger. Their use for both snapshots and time exposures is most clearly explained in the booklet which comes with the camera. About the Publisher Forgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.com This book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully; any imperfections that remain are intentionally left to preserve the state of such historical works.