What is Starlight Level and Low-Light Conditions?

How much do you know about starlight level and low-light conditions?

A low-light camera refers to a surveillance camera that can capture clear images under low light conditions, generally at 0Lux or 0.1Lux.

Illuminance, or light intensity, is a physical term referring to the energy of visible light received per unit area. The unit is Lux, abbreviated as Lx. In the security industry, illuminance is represented in Lux.

0Lux means that the camera can capture images even in complete darkness. Most cameras operate at 0Lux or 0.1Lux, and the required illuminance depends on the aperture size of the lens (F-value), where a smaller F-value corresponds to lower required illuminance.

For color cameras, illuminance ranges from 0.0004LUX to 1LUX, and for black and white cameras, it ranges from 0.0003 to 0.1LUX (with infrared, 0LUX can be achieved). Industry experts believe that the achievable illuminance not only depends on the aperture size (F-value) but also on the conditions under which the Lux value is indicated. Otherwise, it is just a numerical representation without practical significance. In terms of aperture size (F-value), a larger aperture corresponds to a smaller F-value and lower required illuminance.

Levels of minimum illuminance for low-light cameras:

• 0.1Lux: Dim light level

• 0.01Lux: Moonlight level

• 0.001Lux and below: Starlight level

These are CCTV cameras that can operate in extremely weak lighting conditions, even below normal visual response levels.

Illuminance is measured in Lux. 0Lux means the camera can capture images in complete darkness. Most cameras operate at 0Lux or 0.1Lux, and the illuminance value depends on the aperture size of the lens (F-value: the ratio of lens focal length to aperture diameter, with a smaller ratio indicating a larger aperture and higher light transmission). Cameras are available with illuminance ranging from 0.001Lux to 1Lux, and when Lux values reach 0.001, it is considered to have achieved starlight level illuminance.

As the name suggests, low-light cameras refer to cameras that can capture clear images under low-light conditions. There is no unified standard in the CCTV industry for the technical specifications of low-light cameras, making it challenging to define the value at which a camera can be termed as a low-light camera. The lowest illuminance value is related to the lens's aperture size (F-value), electronic sensitivity (ELECTRONIC SENSITIVITY), infrared switch status, and other conditions. Therefore, it is necessary to examine the camera's minimum illuminance under the same test conditions.

The evolution of low-light cameras in the market can be simplified into three steps: Daytime color/nighttime black and white (COLOR/MONO); low-speed shutter (SLOW/SHUTTER); and super-sensitive cameras (EXVIEW HAD).