The minimum illumination of the camera (minimum subject illuminance) is
It is the minimum illumination required by the camera to take pictures.

The lower the minimum illumination value, the better you can shoot in the dark.
If the minimum illumination is low, “a wide range of shooting can be done = the area where the image is displayed increases”
However, the image quality itself also depends on other factors of the camera.

The minimum illuminance of infrared cameras used for nighttime monitoring is 0 lux.
It does not use external light, but emits “infrared rays” that are invisible to the human eye.
In other words, you don’t need any illumination when shooting, and you can shoot in complete darkness.
On the other hand, the minimum illuminance of a high-sensitivity camera is less than 1 lux (0.1~0.002 lux),
Even with ultra-high-sensitivity cameras, the minimum illuminance is set very low at ~0.00001 lux.
Shooting in complete darkness is not allowed.
Also, in order to shoot as a video that can properly check the contents,
The illuminance is about 2.5~3 times higher than the minimum illuminance of the camera.
There is no particular uniform standard for the minimum illuminance value. It is important to note that the numerical values are given according to different measurement methods and standards for each manufacturer.