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a branch of engineering that makes photographic copies (microfilms) of various originals, such as manuscripts, blueprints, figures, and printed text, that are reduced tens or hundreds of times. The process of microfilming is a means of office mechanization. It is used wherever large blocks of documentary information must be handled (for example, at information centers, archives, libraries, and research and design institutions).
As a scientific discipline, microfilming is a branch of the science dealing with reproduction methods. The use of microfilming reduces the size of storage areas by an average of 90–95 percent, provides access for a broad range of readers to rare publications that have great historical or artistic value, helps preserve original documents by eliminating the possibility of damage caused by frequent use, makes possible quick production of copies of a microfilm and printing of full-size copies from it, and reduces shipping costs (since the weight and size of postal parcels are greatly reduced when microfilming is used).
The first works on microfilming date to the early 19th century and are associated with D. Dancer, an English manufacturer of optical instruments, and L. J. M. Daguerre, a French photographer. In Russia, E. F. Burinskii, one of the founders of scientific and forensic photography, was largely responsible for the development of the microfilming of documentary materials. Scientific and technical progress, which brought about a sharp increase in the volume of scientific and technical information, gave rise to the use of microfilming in many areas of production and scientific work.
There are several main types of image carriers: roll microfilm (16-mm, 35-mm, and 70-mm motion-picture film up to 30 m long), strip microfilm (16-mm and 35-mm motion-picture film up to 150 mm long), microfiche (a photographic film measuring 105 X 148 mm), and aperture punched cards (microfilm mounted in a standard punched card, usually an 80-column card). The selection of the type of image carrier depends mainly on the storage and retrieval system used.
The equipment used in microfilming includes units designed for frame-by-frame filming with a fixed carrier (roll microfilm or microfiche) and units for dynamic or slit filming (the carrier and the original move continuously); contact printers for micro-photocopies; units for developing, drying, and editing microfilms; readers for monitoring and reading microfilms; reader-copiers for producing magnified copies of documents (for example, by electrography); and storage equipment (boxes, cabinets, or files).
In principle, microfilming techniques do not differ from normal photography; the only difference is that special optics and photographic and motion-picture film with higher resolution (200–500 lines or more per mm) are used for microfilming. Microfilm duplicates are made on diazo film or on Kalvar film, on which the image is created by very small light-scattering bubbles in the photosensitive layer. When large volumes of information are stored on microfilm, information retrieval systems (such as the Iveriia system for strip microfilm or the Poisk system for roll microfilm) are used for immediate retrieval of needed documents (that is, frames bearing the images of the documents). In this case the document description is entered when the original is filmed; in aperture punched cards the document description is entered on the perforation field of the card.
In the 1960’s and 1970’s, significant progress was made in the production of more advanced photographic materials and microfilming equipment. New materials were produced for instantaneous “dry” processing, and methods of microfilming color originals on color film were developed, thus greatly expanding the information capabilities of microfilm and better conveying the artistic value of the original. Microfilming techniques make possible the production of microfilms with reduction of more than 200 X. In this case, for example, up to 8,000 book pages (that is, more than ten volumes of the Great Soviet Encyclopedia) can be entered on one microfiche. The use of microfilming in computer technology, particularly for the input of information from microfilm into a digital computer and for output on microfilm, is promising. Research is being conducted on the use of laser devices in microfilming.
REFERENCESLukin, V. V. “MikrofiFmirovanie, ego nastoiashchee i budushchee.”
SShA: Ekonomika, politika, ideologiia, 1973, no. 4.
Mekhanizatsiia inzhenerno-tekhnicheskogo i upravlencheskogo truda: Spravochnaia kniga. Edited by I. I. Kandaurov. Leningrad, 1973.
I. M. GOFBAUER