One of the mysteries of the English language finally explained.
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.
Late 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.
In this article we explore how to impress employers with a spot-on CV.