A knowledgeable friend said that the surveillance camera is not clear about how to adjust it.

This is by adjusting the focal length of the camera lens to make the camera picture clear. First remove the camera, take it to the monitoring center, remove the cover glass of the camera lens to expose the lens, and then connect the camera with the monitor. After adding, loosen the small gong wire on the side of the lens with a small gong wire knife, and then start to adjust the lens to the video picture until the picture is clear. Then tighten the copper wire on the side and cover it. (Note: Because the camera is charged, it must not touch objects such as iron. Otherwise, it will burn the machine.