Photomacrography
photomacrography
[¦fōd·ō·ma′kräg·rə·fē]Photomacrography
motion-picture or still photography of medium and small macroscopic (visible to the eye) objects or details in large scale (from 1:5 to 20:1) by means of conventional or special camera or motion-picture lenses (microanastigmats). Photomacrography with high magnification makes it possible to show in a photograph or on a screen not only the visible details and structure of an object but also those that are invisible to the naked eye. Photomacrography is widely used in science, technology, and agriculture as an objective documentation and research method.
Photomacrography is done from close range (6 to 1.05 times the focal length of the optical system), which requires an extension of the camera body equal to f’/m, where/’ is the focal length of the lens and \\/m is the scale of reproduction. The cam length of the lens and 1/m is the scale of reproduction. The camera body is extended by means of protruding lens mountings, extension adaptor rings and attachments, or special equipment. Auxiliary (closeup) lenses, which shorten f’, are sometimes used. The objects to be photographed are mounted on stages, which facilitates focusing and the arrangement of the required lighting and background. Enlargement of the scale in photomacrography greatly reduces the illumination intensity of the image on the photographic material, requiring an increase in exposure time by a factor of (1 + 1/m)2 as compared with conventional photography and decreasing the depth of field, which may be increased by reducing the lens aperture.
REFERENCES
Minenkov, I. B. Makrofotografiia. Moscow, 1960.Ovsiannikov, N. A. Spetsial’naia fotografiia. Moscow, 1966.
Nisskii, A. V. Spetsial’nye vidy kinos”emki, 2nd ed. Moscow, 1970.
I. B. MINENKOV