Special Uses Of Photography Part I

With special cameras, films, and other equipment, photography has been adapted to a wide range of uses in science and industry.

Photomicrography is extremely useful to scientists and engineers. It combines a camera with a microscope. Pictures can be then taken of things too small to be seen with the naked eye. These pictures are called photomicrographs. They enable us to study the cells of living tissue. We can see the crystal structure of a piece of metal or study parts of ancient plants discovered in a thin slice of coal.

X-ray photography is widely used in medicine, industry and science. It is quite different from ordinary photography. X-rays are invisible electromagnetic waves. They behave much like visible light. But they can pass through things such as wood, cardboard, and flesh, which light cannot penetrate. X-rays cannot be focused by a lens, so no camera is used. The subject is placed between an x-ray tube and the film. A special film that is sensitive to X-rays is used. The photograph obtained is a life-size shadow picture.

In medicine, X-rays are used to locate where a bone is broken and to examine internal organs such as the lungs. In an C-ray picture, the bones and denser tissues of the body show up as dark shadows. Healthy muscle shows as a light shadow.

X-ray photographs are used in industry to test and inspect materials and parts. A hidden flaw in a welded joint, for example, shows up in an X-ray photograph. The flaw cannot be detected by the eye. Today, welded joints of pipelines, steel beams, and many other objects are routinely checked by X-ray photography.

Aerial photography has many uses. Photographs taken from the air are of great value to mapmakers and surveyors. These photographs reveal many things that cannot be seen by an observer on the ground. Aerial photographs also help locate mineral deposits. The different landforms and kinds of vegetation that show up in the photograph give clues rock formations beneath the surface. Traffic studies are another important use of aerial photography. Even archeologists make use of aerial photographs. The boundary lines of ancient fields and the sites of long-forgotten, ancient cities and settlements show up clearly in photographs that have been taken from a great height.

One of the chief uses of aerial photography is in military intelligence-the gathering of information about the military strength of other countries. Military specialists study photographs taken from a great height to learn about airfields, fortifications, missile bases, and other military installations.