Fisheye lens is one of the most simple and effective methods to construct panoramic vision. Its prominent feature is that it can absorb all the information in more than 180 degrees at one time, so as to achieve the effect of no blind area. In terms of characteristics, fisheye lens is a special lens with ultra wide angle. The diameter of the front lens of this photographic lens is parabolic and protrudes towards the front of the lens. Its visual effect is similar to that of fisheye observing the scenery on the water. It is a short focal length lens. Generally, the focal length is between F = 6-16mm. According to the principle of optical imaging, the short focal length can show the monitoring effect of large field of view. Use SECULENS Fisheye 1.8mm, panoramic fisheye lens, 360 ° no dark angle!

There are two kinds of common fisheye lenses, one is circular imaging and the other is rectangular imaging. The three-dimensional angle of the former is larger than that of the latter. At present, the fisheye lens selected by most panoramic cameras is the first, because its three-dimensional angle of view can reach 360°x180°, reaching the ideal panoramic angle of view. Although the field of view angle provides unparalleled enjoyment, it is obtained on the premise of sacrificing the original monitoring picture. The deformed image of fisheye lens is generally called barrel distortion. This distortion will be serious with the expansion of field of view angle, but this is also a reasonable phenomenon.

Generally, the field of view angle of the monitoring probe is about 60 degrees - 90 degrees. If there are all large-scale monitoring needs in the monitoring field, if only a few more cameras are installed to cover the monitoring area, it will undoubtedly increase the camera cost and installation cost, and the back-end display and storage cost will also increase accordingly; Even though the ball machine can achieve 360 degree full range monitoring through the PTZ, it can not achieve the 360 degree range of simultaneous monitoring. Moreover, in practical application, most ball machines monitor the scene by setting preset positions, which is difficult to avoid the occurrence of "missing control" of important events.

In the current security market, as the blind spot of video surveillance becomes more and more unbearable, the market has more and more requirements for non blind spot video surveillance system. The panoramic camera is to realize panoramic monitoring. Its emergence can eliminate the blind spot of monitoring in the real sense and ensure the reliability and integrity of video, which is of great significance to users and even the society. One type of panoramic camera is based on ultra wide angle fisheye lens. The fisheye panoramic camera is the transformation and upgrading of the existing monitoring system. In the fisheye panoramic monitoring system, only one fisheye panoramic camera is needed to realize panoramic blind area monitoring without any mechanical parts. The panoramic image of the monitoring site is captured through the ultra wide-angle fisheye lens. According to the different installation methods, the panoramic image of 180 degrees or 360 degrees can be achieved, and the elliptical or circular deformed image can be corrected into a normal video image through embedded or external image processing software. If strictly speaking, the panoramic camera is not a camera, it is a "three in one" panoramic monitoring system composed of fish eye lens HD camera image processing software.