The aperture, shutter speed, and ISO speed exposure settings used in photography are comparable to the width, time, and quantity. Furthermore, natural light is out of a photographer's control, just as the velocity of rainfall was above and out of your control. The shutter of a camera controls whether the sensor is exposed to light coming from the lens or not. The amount of space through which light can enter through your camera lens is controlled by the aperture setting. The ISO speed controls the camera's sensitivity to incoming light.