The lenses of common surveillance cameras are 3.6mm, 4mm, 6mm, 12mm, 16mm, 25mm, etc. What parameters do these refer to?

The lenses of the surveillance camera are 3.6mm, 4mm, 6mm, 12mm, 16mm, and 25 mm. These parameters are the lens focal length values of the surveillance camera.

The smaller the focal length, the wider the angle. 3.6mm means that a person stands about 3.6 meters away from the lens, and the collected image can just show the portrait in full screen. If you want to see far, the focal length must be large, but the viewing angle should be narrow;

If you want to see widely, you have to have a small focal length, but things in the distance are difficult to distinguish. Therefore, it is necessary to choose the appropriate focal length according to the purpose of the surveillance camera.

Extended data:

The corresponding relationship between lens focal length and CCD viewing angle and object distance is as follows:

If the lens size is fixed, the larger the CCD area, the better the imaging quality! If the CCD size is fixed, the larger the lens diameter, the stronger the incident light and the greater the brightness, and the better the imaging quality.

Characteristic analysis of various surveillance cameras;

1, bolt machine: cheap, but it has no zoom and rotation function, and it can only be monitored at a fixed angle, so it has no good concealment.

2. Hemispherical camera: it has certain concealment in appearance. Because of its small size and beautiful appearance, it is suitable for office and high-grade decoration places and can be hung on the ceiling.

3. Integrated camera: built-in lens, automatic focusing, convenient lens control, simple installation and debugging. Life is mostly used in government projects, high-end high-rise buildings, as well as shopping malls, schools, hotels and so on.

4. Infrared camera for day and night: it is a camera device that integrates camera, protective cover, infrared lamp and power supply and cooling unit, and has the advantages of long night vision distance, strong concealment and stable performance.

5. High-speed ball camera: it is expensive and can adapt to high-density and complex monitoring places. The equipment integrates an integrated camera and pan/tilt, and also has the characteristics and functions of fast tracking, 360 horizontal rotation, no monitoring blind area, privacy area shielding and so on.

6. Network camera: the image can be digitally processed and compressed, and the compressed video signal can be sent to the server or client through IP network; On the server side or client side, remote images can be viewed in real time through software.