The visual field : expressed in degrees of angle. This refers to the area that a lens is able to film. The focal length of a lens determines the width of the field of view covered by the camera. A wide-angle lens has a shorter focal length than a telephoto lens, so its field of view is wider.
The opening and the exhibition: The number F defines the opening of the diaphragm of the lens and therefore the amount of light that can pass through it. The smaller the F-number, the greater the ability of the lens to collect light. A small F-value allows you to get a good image even if the area to be monitored is poorly lit. On the other hand, a larger F-value will result in a greater depth of field (a deeper, clearer area between the foreground and background).
Sensitivity Lux : expressed in Lux, it allows to know if a camera is able to film in the dark or not. The lower the value, the higher the sensitivity, meaning that it will be possible to detect movement in the dark.
Night vision The infrared LEDs surrounding the lenses allow outdoor surveillance even at night. As soon as the area to be monitored begins to be in darkness, the camera automatically switches to "night" mode and turns on the LEDs surrounding its lens. Some models can illuminate up to 30 meters. The area to be monitored changes to gray scale.
The autofocus It corresponds to the focus and allows to obtain sharp and precise images.