Monitor the camera's focal length 4 meters good or 8 meters good
General surveillance camera focal length is not 4 meters 8 meters, and some words are estimated that the focal length of the telescope. I think you focus on the unit you did not understand, monitor the camera focal length of 2.4,4,6,8,10 ... and so on
Showing the shooting of the smaller the object, looking very far feeling. The larger the number, the shooting angle is small, shooting the display of the object is closer, look bigger.
The focal length is: mm. The smaller the data, the larger the shooting angle is, and the larger the captured range
