单词 | Petzval |
释义 | Petzval/ˈpɛtsvɑːl/ /ˈpɛtsv(ə)l/Optics and Photography noun Used attributive with reference to various concepts related to a lens system designed by Petzval; specifically Petzval condition noun the condition for freedom from astigmatism of a compound lens, that the sum of the ratios of the power of each element to its refractive index be zero. Petzval lens noun a lens consisting of two widely spaced colour-corrected compound lenses whose negative elements are on the inner sides. Petzval sum noun a number representing the degree of curvature of the field of a compound lens, derived from the refractive indices and surface radii of its elements. OriginLate 19th century; earliest use found in William de Wiveleslie Abney (1843–1920), civil servant and photographic scientist. From the name of József M. Petzval, Hungarian mathematician. |
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