| 释义 |
photovisual, a. (n.)|fəʊtəʊˈvɪʒjuːəl|
Also photo-visual.
[f. photo- 2 + visual a. and n.]
1. Of a lens or an optical instrument: bringing both visible and actinic, non-visible rays to the same focus. Also as n., such a lens or telescope.
1909in Cent. Dict. Suppl. 1922L. Bell Telescope iv. 89 The..objective.. carries the name of ‘photo-visual’ since the exactness of corrections is carried well into the violet, so that one can see and photograph at the same focus. 1955J. B. Sidgwick Amateur Astronomer's Hand-bk. xxiii. 422 For photography a reflector is to be preferred, unless a photovisual is available. 1958J. Strong Concepts of Classical Optics xiv. 323 Three different glasses, properly chosen for their partial dispersions, can be combined in components to yield a composite lens... Fig. 14-14 gives a tabulation..for the three glasses used in the Cooke photo-visual triplet lens. 1964Yearbk. Astron. 1965 191 The main instruments at present are a 13-inch reflector, a 10-inch refractor, a 6-inch photovisual refractor, a 16 centimetre transit telescope and various cameras. 1977Sci. Amer. Sept. 29/2 (Advt.), Sixth, the design must be photovisual so that he could record on film whatever these superior optics would present to the eye.
2. Astr. Applied to stellar magnitudes determined in terms of the spectral response of the eye by photographic or photoelectric means.
1914Carnegie Inst. Yearbk. 1913 214 The comparison of these ‘photovisual’ results with the ordinary photographic magnitudes shows an increase in the color index as the variable approaches its minimum. 1927H. N. Russell et al. Astron. II. xviii. 620 With isochromatic plates and a ‘color filter’ to cut off the blue and violet light and let through the green and yellow, magnitudes may be obtained which agree very closely with the visual scale. These are called photo-visual magnitudes. 1958C. C. Adams et al. Space Flight 132 At this time it is expected to be of the fifth photovisual magnitude, which is about the same brightness as the faintest star that, under reasonably good observing conditions, can be seen with the naked eye. 1963C. W. Allen Astrophysical Quantities (ed. 2) x. 195 The effective wavelengths of a colour index system change with the colour itself. The U.B.V. system..has replaced the international photographic and photovisual systems. |