| 单词 | spot lens |
| 释义 | > as lemmasspot lens spot lens n. (a) Microscopy a condensing lens having a black spot painted in the centre or an opaque disc mounted below to intercept direct light, used for dark-field illumination; (b) a lens which focuses the output of a lamp into a narrow beam; the lens of a spotlight. 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 1855 J. Quekett Pract. Treat. Use Microscope (ed. 3) ii. ii. 221 The blackground illumination may also be effected by..a nearly spherical lens, having its centre covered with a disc of tinfoil; this instrument is known as the ‘spotted lens’. 1857 L. S. Beale How to work with Microscope ii. 16 This little instrument which I now show you is termed a spot-glass, and consists of a plano-convex lens... In the centre of the flat surface is placed a small circular piece of black paper in order to prevent the passage of any direct rays of light.] 1860 G. Rainy in Glasgow Med. Jrnl. Oct. 283 The observer is as it were looking at the retina through an apparatus similar, in certain respects, to that known as a spot lens. 1903 Proc. Acad. Nat. Sci. Philadelphia 1902 54 793 The lorica shows yellowish-brown by transmitted light, bluish-green with a brown edge with spot-lens. 1945 Pop. Photogr. Mar. 8/2 (caption) No. 17 Spotlight..with spot lens. 1998 P. A. Annis & T. W. Quigley in J. Summerscales Microstruct. Characterisation Fibre-reinforced Composites ii. 27 To optimize reflected illumination, we use free standing fiber optic illuminators with spot lenses and/or a fiber optic ring illuminator attached to the objective of our stereo microscope. 2013 H. C. Box Set Lighting Technician's Handbk. (ed. 4) x. 235 A Nila daylight with flood lens gives 32 fc [= footcandles] at 10 ft. With the spot lens it gets 180 fc at the same distance. < 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。