| 单词 | effective aperture |
| 释义 | > as lemmaseffective aperture effective aperture n. Optics the diameter of the widest beam of light incident on an optical system that goes to form an image; also in extended use (e.g. in connection with radio waves or particle beams). ΚΠ 1844 Littell's Living Age 14 Dec. 412/1 Messrs. Merz and Mahler, of Munich, have more recently executed..an Achromatic Telescope whose object glass has 15 inches of effective aperture, and a focal length of 322 feet. 1887 Proc. Royal Soc. 1886 41 282 We may elude the objection by contracting proportionally the effective aperture, but only at the expense of brightness. 1965 M. J. Langford Basic Photogr. iii. 54 As the aperture closes the diameter of this incident light beam or ‘Effective Aperture’ narrows proportionally. 1995 Sci. Amer. Feb. 57/1 Radio astronomers have developed methods for combining signals from radio telescopes scattered around the globe, creating an effective aperture 8,000 miles across. < as lemmas |
| 随便看 |
英语词典包含1132095条英英释义在线翻译词条，基本涵盖了全部常用单词的英英翻译及用法，是英语学习的有利工具。