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Aplanat |
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Aplanat
a photographic objective with an optical system consisting of two achromatic lenses placed symmetrically about the diaphragm. The aplanat is free from spherical aberration, chromatic aberration, and distortion; but astigmatism, though severely attenuated, remains present. Because of its simplicity of design and loose mounting requirements, the aplanat lends itself readily to use as a universal lens with a relative aperture from f/8—rarely f/5 (for portrait work and group photographs)—to f/16 (as a wide-angle lens). With the appearance of anastigmats, aplanats lost their significance and are now produced in small quantities. REFERENCELapauri, A. A. Fotograficheskaia optika. Moscow, 1955.Want to thank TFD for its existence? Tell a friend about us, add a link to this page, add the site to iGoogle, or visit the webmaster's page for free fun content. |
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