When does DJI 4 open the mechanical shutter and use the electronic shutter?

Mechanical shutter is easy to understand: controlling the opening and closing of several blades by spring or electromagnetic means, or "crossing" the imaging field of view window from left to right or up and down with a gap of a certain width like a stage curtain, so that the window can get a "chance to see light" within a specified length of time-this has produced the general concept of mechanical shutter.

The electronic shutter, in fact, does not have a "door", but uses the principle that the CCD does not work without electricity. When the CCD is not powered on, although the image field window is "wide open", it cannot produce an image. If the electronic time circuit is used when the shutter button is pressed, so that the CCD is energized only for a specified period of time, the same effect as the shutter "instantly opens" can be obtained. Therefore, a digital camera with an electronic shutter is "silent" when the shutter is pressed. But in order to meet the "psychological needs" of film friends, some cameras can set up an "electronic sound": simulate a "click" sound to make you "addicted").