How wide can a square surveillance camera shoot?

The recording range of the surveillance camera depends on the lens with different parameters. Just like our eyes or glasses worn by nearsighted people, the shorter the focal length, the closer we look, and the wider the scope; On the contrary, the longer the focal length, the farther you can see and the smaller the relative visible field of view.

A camera with a lower configuration is similar to a camera with a distance of about 6 meters and a lens of 3.6mm; If the distance is longer, 25mm is used for those about 80 meters. And the resolution is the clarity of the video, SXGA( 1280? x？ 1024) is 1.3 million pixels, VGA(640? x？ 480) is 300,000 pixels.