Knowledge of low-light cameras

No matter the manufacturer or importer of low-illumination cameras advertised on the market, the definition of low-illumination is divergent. There is no consensus that color cameras range from 0.0004 LUX to 1 LUX, and black-and-white cameras range from 0.0003 to 0.1 LUX. Up to 0LUX), this is the situation that the domestic market does not have a unified standard in the technical specifications of the CCTV industry, and each speaks. Industry insiders emphasized that how low the illuminance can be depends not only on the aperture size (F value) of the lens, but also on the conditions under which the indicated LUX value can appear, otherwise it is just a digital game! In terms of aperture size (F value), the larger the aperture, the smaller the F value it represents and the lower the illuminance required. In addition, has the electronic sensitivity (ELECTRONIC, SENSITIVITY) been increased, and what is the cumulative number of frames on a single screen? Is infrared light ON or OFF? … Etc. should be understood clearly so as not to be confused by the illuminance values ​​indicated in the specifications. The evolution of low-light cameras in the Chinese market The evolution of low-light cameras in the Chinese market is simply divided into the following three steps: daytime color / night black and white (COLOR / MONO) low-speed shutter (SLOW / SHUTTER) and super-sensitivity camera (EXVIEW / HAD) .

1. Daytime color / black and white at night (Day and night camera COLOR / MONO)
Such cameras still have their specific demand groups in the market. The minimum illuminance of the COLOR / MONO camera on the domestic market is even 0LUX. We can't help but ask: "The camera is made of optical principles. How to image at 0 illuminance?" Color / Mono The camera makes use of the black and white image's high sensitivity to infrared rays. Under certain light source conditions, it uses line switching to convert the image from color to black and white to make it easier to match infrared. During the technological evolution of color / black and white line conversion, this type of camera has adopted a single CCD (color) design. It is a color camera during the day or when the light source is sufficient. It is used when night comes or the light source is insufficient (generally between 1LUX and 3LUX) The digital circuit eliminates the color signal and becomes a black and white image. In order to match the infrared, the infrared filter that is indispensable for the color camera is also removed. The true "low-illumination camera" should refer to the camera itself (the components and technologies used) The function that can be achieved, and the color / black and white camera during the day is limited by the CCD sensitivity, and it cannot be changed by itself. It only uses line switching and infrared light to enhance the function. It cannot be regarded as a low-light camera.

2. Low-speed shutter (SLOW / SHUTTER)
This type of camera is also called (screen) cumulative camera. It uses the technology of computer memory to continuously accumulate several pictures that are more blurred due to insufficient light to form a clear picture. The SLOW SHUTTER technology is used to reduce the camera. Illumination is 0.008LUX / F1.2 (& # 215; 128), and the number of frames (128 frames) that can be accumulated on the screen is a leading level even including imported brands. This type of low-light camera is suitable for museums that are prohibited from damage by red and ultraviolet rays, night biological activity observation, night military coastline monitoring, etc., and the monitoring of relatively static properties.

3. Super-sensitivity camera (EXVIEW / HAD)
Super-sensitivity camera (EXVIEW / HAD), also known as 24-hour camera, its color illuminance can reach 0.05LUX, black and white can reach 0.003-0.001LUX (also can be matched with infrared to achieve 0LUX) not only can clearly identify the image, but also Real-time continuous picture.