A slow shutter speed means that you need more light; a fast shutter speed means you need less light.

较慢的快门速度意味着您需要更多光线；较快的快门速度意味着您需要较少的光线。

He said the system is similar to a camera with a fast shutter speed that permits a photographer to capture a Formula One race car as it crosses the finish line.

他说，该系统类似于快门速度很快、可以让摄影师捕捉到一级方程式赛车冲过终点线的画面的相机。