To minimise the temperature gradient across the sample, the light aperture in the block is only2.5 mm?.

为了减小样品上的温度梯度，台体上的光孔直径只有2.5毫米。

youdao

The only light came through a narrow aperture.

仅有的光亮来自一个小孔。

《新英汉大辞典》

You get the same amount of light with a large aperture and a fast shutter speed as you do with a small aperture and a slow shutter speed.

你使用大光圈以及慢速快门所得到的光和你使用小光圈以及高速快门得到的光是一样多的。

youdao

He left it on a fixed aperture, so that as the light faded, the exposure got ever longer.

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Light entering through a lens is focused through an aperture and exposure is controlled by a shutter.

FORBES: Technology briefing

The aperture is used to focus different wavelengths of light in different parts of a scene onto a detector.

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