achromatn.

Brit.

/ˈakrə(ʊ)mat/, U.S.

/ˈækrəˌmæt/

Origin: Of multiple origins. Partly formed within English, by clipping or shortening. Partly a borrowing from German. Etymons: achromatic n.; German Achromat.

Etymology: Originally (in quot. 1873) shortened < achromatic n. In later use independently < German Achromat (O. Lummer 1897, in Zeitschr. f. Instrumentenkunde Aug. 228), back-formation < achromatisch achromatic adj.

Optics.

An achromatic lens. Also achromat lens.

ΘΚΠ

the world > physical sensation > sight and vision > optical instruments > lens > [noun] > other lenses

concave1632

globe1653

meniscus1693

hemispherule1696

convex1705

omphaloptic1728

omphalopter1738

crown lens1764

achromatic1785

condenser1798

meniscus lens1820

Fresnel lens1835

bull's-eye1839

Stanhope lens1850

spot lens1860

amplifier1866

achromat1873

projectora1884

aplanat1890

triplet condenser1892

Aldis lens1902

monocentric1922

Schmidt correcting plate1934

coated lens1948

Panavision1955

Schmidt correcting lens1961

re-imaging1962

1873 Overland Monthly Feb. 174/2 Our lenses penetrate substances previously supposed to be opaque. Our achromats have been able to perceive the billows upon star-beaches.

1900 S. P. Thompson tr. O. Lummer Contrib. Photogr. Optics vii. 41 These two-lens combinations corrected in this sense achromatically and spherically we shall henceforth call achromats.

1942 J. Mitchell Ilford Man. Photogr. i. 20 The maximum aperture at which a single achromat can be used is about f/14.

1982 N.Y. Times 4 July ii. 24/6 There are two types of telescopes suited to this kind of photography: refractors which use a two-element achromat lens, and reflectors, utilizing a highly polished precision ground mirror.

1995 Sky & Telescope May 35 (advt.) A relatively short focus objective that is superior to long focus achromats in contrast and definition of subtle planetary detail.

This entry has been updated (OED Third Edition, September 2009; most recently modified version published online December 2021).

单词	achromat
释义	achromatn. Brit. /ˈakrə(ʊ)mat/, U.S. /ˈækrəˌmæt/ Origin: Of multiple origins. Partly formed within English, by clipping or shortening. Partly a borrowing from German. Etymons: achromatic n.; German Achromat. Etymology: Originally (in quot. 1873) shortened < achromatic n. In later use independently < German Achromat (O. Lummer 1897, in Zeitschr. f. Instrumentenkunde Aug. 228), back-formation < achromatisch achromatic adj. Optics. An achromatic lens. Also achromat lens. ΘΚΠ the world > physical sensation > sight and vision > optical instruments > lens > [noun] > other lenses concave1632 globe1653 meniscus1693 hemispherule1696 convex1705 omphaloptic1728 omphalopter1738 crown lens1764 achromatic1785 condenser1798 meniscus lens1820 Fresnel lens1835 bull's-eye1839 Stanhope lens1850 spot lens1860 amplifier1866 achromat1873 projectora1884 aplanat1890 triplet condenser1892 Aldis lens1902 monocentric1922 Schmidt correcting plate1934 coated lens1948 Panavision1955 Schmidt correcting lens1961 re-imaging1962 1873 Overland Monthly Feb. 174/2 Our lenses penetrate substances previously supposed to be opaque. Our achromats have been able to perceive the billows upon star-beaches. 1900 S. P. Thompson tr. O. Lummer Contrib. Photogr. Optics vii. 41 These two-lens combinations corrected in this sense achromatically and spherically we shall henceforth call achromats. 1942 J. Mitchell Ilford Man. Photogr. i. 20 The maximum aperture at which a single achromat can be used is about f/14. 1982 N.Y. Times 4 July ii. 24/6 There are two types of telescopes suited to this kind of photography: refractors which use a two-element achromat lens, and reflectors, utilizing a highly polished precision ground mirror. 1995 Sky & Telescope May 35 (advt.) A relatively short focus objective that is superior to long focus achromats in contrast and definition of subtle planetary detail. This entry has been updated (OED Third Edition, September 2009; most recently modified version published online December 2021). < n.1873
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