How to choose the monitoring focal length
With the constant updating of security equipment, various types of monitoring equipment have emerged. Based on the different installation environments and use scenarios, there are many types of monitoring equipment. Many friends don't know how to choose the monitoring focal length when choosing a surveillance camera. Today, Wuxi Dehang Technology Co., Ltd. introduces some things to pay attention to when choosing the monitoring focal length.
Select according to the monitoring range:
There are many kinds of monitoring nowadays. In the early years, the monitoring focus was fixed, but now the monitoring image can be manually controlled, and the monitoring focus determines the size and distance of the monitoring image of the surveillance camera. If the camera is installed indoors and the monitoring range is small, it is necessary to choose a camera with a smaller focus, such as a camera with a focus of 3~6mm, because the exposure distance of this type of camera is within 10 meters, but the camera and view angle are large, which can reach more than 45~70 °, especially suitable for indoor or small area monitoring.
Select according to the installation environment:
Essentially, apart from some high-end surveillance cameras, most of them have a fixed focus. The choice of monitoring focus varies according to the installation environment.
Take the outdoor environment as an example. If the installation environment is complex and the distance is far, the camera with large focus must be selected. Take the monitoring camera with 12mm~16mm as an example. The camera focus in this section is suitable for monitoring the distance of 20~50m, but because of the large focus, the monitoring angle range will become much smaller, generally about 15~30 °.
If the monitoring site is rectangular and the monitoring area is far away from the surveillance camera, it is most appropriate to select a large focus surveillance camera.
Select according to user requirements:
The size of the monitoring focal length affects the overall effect of the monitoring camera. The larger the focal length value, the farther the monitoring area will be exposed, but the angle of exposure will also become smaller; The smaller the focal length value, the closer the monitored irradiation area will be, but the irradiation angle will become much larger.
If you need to select the monitoring focal length, it is better to select it according to the user's needs. When you select monitoring, you should not only look at the focal length, but also see the definition and other functions. The definition of some monitoring will change with the change of focal length. In general, the monitoring with a small focus is suitable for taking close shots, while the monitoring with a large focus is suitable for taking long shots.
In general, the use of near focus surveillance cameras within 10 meters; In use focal length surveillance camera with an area of 20 meters; Use a telephoto camera with an area of 50 meters. However, due to different focal lengths, the range of exposure is also different. In the case of uncertain monitoring area and installation environment, the options given are theoretical and only for reference. In most cases, the monitoring area network is composed of multiple surveillance cameras, so the choice of focus is different.
