also: アパーチュア · アパーチャー
noun
A technical term used in optics, photography, and physics to refer to an opening that controls the amount of light passing through a lens or optical system.
カメラのアパーチャを調整して、被写界深度を変える。
Adjust the camera's aperture to change the depth of field.
このレンズの最大アパーチャはF2.8です。
The maximum aperture of this lens is f/2.8.