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单词 vignetting
释义

vignetting


vi·gnette

V0097800 (vĭn-yĕt′)n.1. A decorative design placed at the beginning or end of a book or chapter of a book or along the border of a page.2. An unbordered picture, often a portrait, that shades off into the surrounding color at the edges.3. a. A short, usually descriptive literary sketch.b. A short scene or incident, as from a movie.tr.v. vi·gnet·ted, vi·gnet·ting, vi·gnettes 1. To provide (a photograph or image) with indistinct or fading edges.2. To describe in a brief way.
[French, from Old French, diminutive of vigne, vine (from the use of vine tendrils in decorative borders); see vine.]

vignetting

(vɪˈnjɛtɪŋ) n1. (Photography) the technique of producing a photographic vignette, esp a portrait, by progressively reducing the amount of light falling on the photographic surface towards the edges2. (Photography) the reduction in area of a light beam passing through a camera lens as the obliquity of the beam is increased

vignetting

A method of producing a band of color or tone on a map or chart, the density of which is reduced uniformly from edge to edge.
Translations
vignettatura

vignetting


vignetting

(vin-yet -ing) Uneven or reduced illumination over the image plane in a telescope, camera, etc., leading for example to an image that is dimmer at the edges.

Vignetting

 

the partial darkening of a bundle of light rays entering an optical system, which is accomplished by restricting the light with the apertures of the instrument. Vignetting leads to a gradual decrease in the illumination of an image in the transition from the center to the edge of a field of vision. It is totally absent only when the plane of the entrance aperture coincides with the plane of the object (correspondingly, when the plane of the exit aperture coincides with the plane of the image). In this case, the image is sharply limited. There is another form of vignetting, achieved in mirror and mirror-lens systems through the use of a second reflecting element, which hinders the dissemination of the central rays.

Vignetting is important in the use of photographic lenses. It usually does not exceed 30-40 percent, but in wide-angle lenses it can reach 50-60 percent. As a result, the edges of the photographic film seem incompletely exposed. Vignetting should be considered in spectrum analysis—for example, when there must be even illumination along the full height of the image of the spectrographic slit.

REFERENCES

Tudorovskii, A. I. Teoriia opticheskikh priborov. Part 1. Moscow-Leningrad, 1948.
Mandel’shtam, S. L. Vvedenie v spektral’nyi analiz. Moscow-Leningrad, 1946.

vignetting

[vin′yed·iŋ] (optics) Reduction in intensity of illumination near the edges of an optical instrument's field of view caused by obstruction of light rays by the edge of the aperture.

vignetting

(1) A defect of an optical system in which light at the edges of images is cut off or reduced. It is caused by an obstruction in its original construction; for example, when the elements used in a lens are too small.

(2) A visual effect of darkened corners used to help frame an image or soften the frame outline.

vignetting


vignetting

 [vin-yet´ing] the presence of a brighter light intensity at the center of the fluoroscopic image on an image intensifier than at the periphery of the field.

vignetting 

1. A graduated reduction in retinal illuminance due to light reaching the pupil at very oblique angles. 2. The difference in absorption between the two portions of photochromic fused bifocal lenses when the segment is not made of photochromic glass. See photochromic lens; retinal illuminance.
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更新时间:2025/3/20 12:28:38