photovisualadj.n.
/ˌfəʊtə(ʊ)ˈvɪʒʊ(ə)l/, /ˌfəʊtə(ʊ)ˈvɪzjʊ(ə)l/, U.S. /ˌfoʊdoʊˈvɪʒ(ə)wəl/, /ˌfoʊdoʊˈvɪʒ(ə)l/; see also visual adj. Astronomy.
1. Designating or relating to a lens or optical instrument that brings to the same focus both visible light and light that can only be detected photographically (usually ultraviolet). Also as n.: such a lens or telescope.
ΘΚΠ
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
1899 Harper's Mag. Feb. 410/2 An English firm now advertises its readiness to supply ‘photo-visual’ object-glasses as large as twenty inches in diameter.
1922 L. Bell Telescope iv. 89 The..objective..carries the name of ‘photo-visual’ since the exactness of corrections is carried well into the violet, so that one can see and photograph at the same focus.
1955 J. B. Sidgwick Amateur Astronomer's Handbk. xxiii. 422 For photography a reflector is to be preferred, unless a photovisual is available.
1964 Yearbk. Astron. 1965 191 The main instruments at present are a 13-inch reflector, a 10-inch refractor, a 6-inch photovisual refractor, a 16 centimetre transit telescope and various cameras.
1994 Sky & Telescope May 35 (advt.) It is 5 times smaller than the color error of a Fluorite doublet over the 4000 to 7000Å photovisual spectrum.
2. Designating a stellar magnitude determined in terms of the spectral response of the eye by photographically mimicking this response using colour filters.
ΘΚΠ
the world > the universe > star > star-matter > [adjective] > magnitude
photovisual1913
1913 Science 25 Apr. 649/1 The photographic and photovisual magnitudes of the comparison stars were determined.
1958 C. C. Adams et al. Space Flight 132 At this time it is expected to be of the fifth photovisual magnitude, which is about the same brightness as the faintest star that..can be seen with the naked eye.
1963 C. W. Allen Astrophysical Quantities (ed. 2) x. 195 The effective wavelengths of a colour index system change with the colour itself. The U.B.V. system..has replaced the international photographic and photovisual systems.
1997 Astron. Jrnl. 113 1884 Photovisual magnitude differences determined from multi-exposure photographic plates for 169 double stars are presented.
This entry has been updated (OED Third Edition, March 2006; most recently modified version published online March 2022).
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adj.n.1899