Monitor the camera lens focal length is what the situation according to the scope of the big focal point what the situation according to the clear
The larger the focal length, the smaller the field of view, the larger the person in the picture, the clearer the detail.
The smaller the focal length, the larger the field of view, the smaller the number of people in the corresponding picture;
Dome cameras generally have 2.5mm, 3.6mm, 6.0mm.
