Let’s have a simple understanding of the basic knowledge of surveillance cameras. The main purpose is to popularize it for everyone. If you do this, ignore it directly and try not to use textbook language.
01. Composition of surveillance camera:
It is mainly composed of 4 large parts and 3 small parts.
Major accessories: camera chip, lens, lamp board, shell.
Small accessories: tail line, lens base, copper column, etc.
Usually, the tail line of the network camera is a network cable interface and the other is a power cable. If it is a Poe camera, there is a network cable interface. The reason why the price of cameras of different brands is the same as that of pixels, but the price varies a lot is mainly due to the difference in the quality of materials used in these accessories. People with strong hands-on ability can assemble one by themselves to try the effect.
02. Camera chip:
The most important part of the surveillance camera is the chip, which is equivalent to the brain of the camera. The chip is embedded on the motherboard, so sometimes it is directly called the camera motherboard, which is divided into CCD motherboard and CMOS motherboard. The two important parts of the chip are imaging sensor and chip processor.
The knowledge of CCD and CMOS is not discussed here. It is usually OK to know nouns. Friends with strong thirst for knowledge can take a look at Baidu. It is estimated that I copy it, and you also skip this paragraph. However, we should understand the difference between CCD camera and CMOS camera:
CMOS fabrication process is simpler than CCD
CMOS is cheaper than CCD
CMOS consumes more power than CCD
CMOS noise is larger than CCD
CMOS sensitivity is worse than CCD
CMOS resolution is lower than CCD
03. Camera lens
The camera lens is divided into large lens and small lens from the appearance. Just know that. Just look at the picture.
The key knowledge of lens lies in focal length and aperture.
Focal length: we usually say how many millimeters of lens we need. Generally 4mm, 6mm, 8mm, 12mm, etc.
Aperture: refers to the F value on the lens, generally f1.0, f1.2, f1.4 and f1.6.
The larger the number of millimeters of the lens, the smaller the viewing range and the farther the distance. For example, the workshop and warehouse usually use 4mm lens; According to the residential building unit door, it is usually 6mm; According to the fence, the path is usually 12mm. Of course, I don’t think it should be flexibly selected and used according to the specific application.
The smaller the F value of the aperture, the greater the luminous flux, and the more expensive the lens is.
04. Camera light panel
Common camera light panels include: array infrared lamp, ordinary infrared lamp and white light panel.
The function of the light panel is to provide auxiliary light source for the lens at night, so that the lens can sense infrared light and become an image. If the delivery effect of the light panel is not good for various reasons, it can also be equipped with an auxiliary light source separately.
05. Camera housing
There are various shapes of camera shell, generally including gun type, hemispherical and spherical. There are aluminum and plastic materials. Specific different manufacturers and different brands are different, and there is nothing to say.