英和和英

別の表記

• dioptra
• dioptre
• dioptry (obsolete)

語源

From Latin dioptra, from Ancient Greek διόπτρα (dióptra). (Can this etymology be sourced?)

発音

名詞

diopter (plural diopters)

1. A unit of measure of the power of a lens or mirror, equal to the reciprocal of its focal length in meters. Myopia is diagnosed and measured in diopters.
2. The dioptre adjustment mechanism of a pair of binoculars or of a camera viewfinder.
3. (photography, dated) A lens element attached to the front of a photographic lens to shorten the lens's minimum focus distance; also called a "close-up filter".
4. (obsolete) Any lens system, such as a telescope.
5. (obsolete) A theodolite or similar surveyor’s angle measuring device.
6. (obsolete) An alidade.
7. (obsolete) A surgical speculum.
8. (obsolete) An instrument for drawing the skull by projections.

参照

アナグラム

• dioptre, peridot, periodt, proetid, proteid, protide, pterido-, pteroid, reptoid