asphericadj.
/əsˈfɛrɪk//eɪsˈfɛrɪk/ Not spherical.
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the world > physical sensation > sight and vision > optical instruments > lens > [adjective] > types of lenses
convex?a1560
planoconvex1665
concavo-convex1677
convexo-concave1693
strong1732
aplanatic1799
periscopic1803
omphaloptic1819
polyzonal1823
shallow1837
first-order1846
periscopical1846
orthoscopic1853
rectilinear1874
overcorrected1875
sphero-cylindrical1881
wide-aperture1882
afocal1887
apochromatic1887
anastigmatic1890
telecentric1892
photovisual1899
aspherical1922
aspheric1923
multifocal1928
plano1944
demagnifying1959
1923 W. R. Rayton in Jrnl. Optical Soc. Amer. 7 197 Osculating paraboloids are, in general, much closer approximations to the required aspheric surfaces than are the osculating spherical surfaces.
1932 A. C. Hardy & F. H. Perrin Princ. Optics xvi. 347 Any surface having other than a plane or spherical form is said to be aspheric... Aspheric surfaces are used to reduce the spherical aberration.
1948 Electronic Engin. 20 314 An aspheric plastic objective lens..focuses infra-red radiation from a distant beacon on to the photo~cathode.
Derivatives
aspheˈricity n. want of sphericity.
ΘΚΠ
the world > physical sensation > sight and vision > optical instruments > lens > [noun] > qualities of lenses
power1673
refracting angle1676
resolution1831
depth of focus1852
astigmatism1859
aplanatism1869
apochromatism1887
covering power1895
coverage1936
asphericity1944
parfocality1955
1944 Jrnl. Optical Soc. Amer. May 279/2 The asphericity of its plates is about four times greater than the asphericity of a parabolic mirror of the same diameter.
This entry has not yet been fully updated (first published 1972; most recently modified version published online June 2019).
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adj.1923