At night, an open flashlight is on the table, and the moment the light emits is captured by a high-speed camera, the light emitted by the flashlight is obvious and cylindrical. Give the light a close-up.
And the moment the light emits is captured by a high-speed camera, the focal length of the camera is between one and two times the focal length. The light emitted by the flashlight is noticeable and cylindrical in shape.
