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開口数 (kaikousuu) Japanese meaning: numerical aperture | Kotomora

開かい口こう数すう

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い

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う

Meanings

1

numerical aperture

Technical term in optics and photography; measures the light-gathering ability of a lens.

このレンズは開かい口こう数すうが大おおきいので、暗くらい場ば所しょでもよく写うつる

。

This lens has a large numerical aperture, so it performs well even in dark places.

Kanji

開open, unfold, unseal
口mouth
数number, strength, fate

Built from

開かい口こう+数すう

Etymology

Compound of 開口 (opening) and 数 (number), a calque of English 'numerical aperture'.