ABSTRACT
The use of a supplementary lens for close-up work has many advantages. The simple teleconverter system increases the focal length of a prime lens while retaining the close focus limit of the focusing mount of that lens. The precise framing and focusing of subjects in close-up work requires a focusing screen showing the image formed by the actual lens in use. The perspective in a photograph depends mostly upon viewpoint. The perspective of close-up photography is much improved by a more distant viewpoint. The fundamental parameter of close-up arrangements in terms of optics is the magnification or magnification range possible. The very long bellows extension required for high magnification photomacrography necessitates lenses of short focal length for convenience. A number of other systems are used successfully for close-up photography and photomacrography. Photomacrography has the normal photographic problems of providing illumination of the correct quality for the film type and in a sufficient quantity to allow exposure at the required aperture.
