| 释义 |
actinograph|ækˈtɪnəgrɑːf, -æ-|
[f. actino- + γράϕ-ος writing. Cf. Gr. ἀκτῑνογραϕία.]
a. An instrument, invented by Sir J. Herschel in 1838, for recording the variations in the power of the solar rays.
1840Sir J. Herschel Phil. Trans. i. 46 Description of an Actinograph, or self-registering Photometer for meteorological purposes. 1853R. Hunt Man. Photog. 154 The instrument constructed by Sir John Herschel, which he has named an actinograph, not only registers the direct effect of solar chemical radiation, but also the amount of general actinic power in the visible hemisphere.
b. spec. Photogr. An instrument (of which there are various kinds) used for recording the actinic power of the light, to determine the correct time of exposure for a photographic plate. (Disused.)
1890Anthony's Photogr. Bull. III. 432 The actinograph [before us] is..an ingenious application of the slide rule for the purpose of determining photographic exposures. 1902Encycl. Brit. XXX. 702/1 In Hurter & Driffield's ‘Actinograph’, the light coefficient is given by a printed card showing the curves for every day in the year. |