apochromatic

American  

[ap-uh-kroh-mat-ik, -oh-kruh-] / ˌæp ə kroʊˈmæt ɪk, -oʊ krə- /

adjective

Optics.

1. corrected for spherical aberration at two wavelengths or colors and for chromatic aberration at three wavelengths.

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apochromatic British  

/ ˌæpəkrəˈmætɪk, ˌæpəˈkrəʊməˌtɪzəm /

adjective

1. (of a lens) almost free from spherical and chromatic aberration

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Other Word Forms

• apochromatism noun

Etymology

Origin of apochromatic

First recorded in 1885–90; apo- + chromatic

Example Sentences

The best telescope objectives, and photographic objectives intended for three-colour work, are also apochromatic, even if they do not possess quite the same quality of correction as microscope objectives do.

From The Project Gutenberg Encyclopedia Volume 1 of 28 by Project Gutenberg

Threads up to about one twenty-thousandth of an inch in diameter may be sufficiently well measured by means of a Zeiss "4 centimetre apochromatic object-glass" and an eyepiece "No. 6" with sixteen centimetre tube length.

From On Laboratory Arts by Threlfall, Richard

In consequence of its low refractive and dispersive power, colourless pellucid fluor-spar is valuable in the construction of apochromatic lenses, but this variety is rare.

From Encyclopaedia Britannica, 11th Edition, Volume 10, Slice 5 "Fleury, Claude" to "Foraker" by Various