With different viewing angle widths, the smaller the number of mm, the larger the area at the same distance. 4mm, 6mm and 8mm of the camera refer to the lens focal length.
The larger the focal length value, the farther you can see, and the smaller the field angle; The smaller the focal length value, the closer you see, and the larger the field angle.
Select according to the scene: a smaller room has a larger field of view angle, and you can select a 4mm lens. For scenes that need to be seen far away, such as corridors and passages, it is recommended to select 6-12mm lens.
Select as needed: select 8mm if you want to take a farther picture. If you want to capture a wider picture, choose 4mm, and choose 6mm in the middle.
