Marion and Co., compiler · London : Marion and Co. · leaf 80
72 PRACTICAL GUIDE TO PHOTOGRAPHY. gether at a point on the wall, but spread over a disc a little larger than the hole in the shutter. If we make … the hole very small, so as to get sharp definitions, we let through so little light that the image is scarcely visible at all. What we want in this case is a lens. The effect of plac- ing a lens in the hole will be that, although the opening is of large size, the rays of light will nevertheless…
