| 释义 |
achromat|ˈækrəʊmæt|
[a. G. achromat (O. Lummer 1897, in Zeitschr. f. Instrumentenkunde Aug. 228), f. achromatisch achromatic a.]
An achromatic lens. Also achromat lens.
1900S. P. Thompson tr. O. Lummer's Contrib. Photogr. Optics vii. 41 These two-lens combinations corrected in this sense achromatically and spherically we shall henceforth call achromats. 1902Bolas & Brown Lens vii. 71 A ‘new achromat’—to use again the designation of Professor Silvanus Thompson for a lens in which the positive member consists of glass of higher refraction with lower dispersion—has its cemented surface positive or converging. 1942J. Mitchell Ilford Man. Photogr. i. 20 The maximum aperture at which a single achromat can be used is about f/14. 1977Nature 23 June 738/1 The flat-field objectives, both achromats and apochromats, are completely new designs, giving improved colour corrections over the widest 25 mm field of view. 1982N.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. |