快门英语是 "shutter"。这个词来自英语单词 "shut"，意思是关闭。快门是指摄影机中的一个装置，它能够控制曝光时间，从而决定照片的亮度。

例句：

The photographer adjusted the shutter speed to capture the fast-moving car.

I need to clean the dust from the shutter blades to improve the image quality.

The shutter on my camera is stuck and won't open.

请注意，在电影摄影术中，"shutter" 还有一个特殊的含义，即指电影摄影机中的一个装置，用来分割画面，并在每一帧之间插入间隙。这种装置通常被称为 "frame shutter" 或 "gate"。例句：

The frame shutter on the movie camera was causing a flicker in the footage.

The director called for the camera operator to open the gate and start rolling.