Unlike during daytime where the basis is (roughly) a 18% gray card, there is not really a consistent, commonly agreed upon way to expose night photos.

白天摄影大致只需要一张18%灰卡，夜间摄影与之不同，没有一致公认的固定曝光值。

youdao

A neutral gray card may be used to set exposure at a consistent level before placing the subject in the scene.

可以在拍摄前使用一张中性灰色卡片放在一个稳定高度来设置曝光。

youdao

On our table in the garden we put a blue card, and all around this blue card we put a number of different gray CARDS.

我们把一张蓝色的卡片放到花园里的桌子上，再在这张蓝色卡片的周围放上若干张不同的灰色卡片。

youdao

"Surcharges for credit or debit card payments are ... especially unfair, " says Gray.

CNN: STORY HIGHLIGHTS

Three weeks before California was set to vote on Governor Gray Davis' recall, a federal appeals court postponed the election because of worries about flawed punch-card voting systems.

FORBES: Magazine Article