Correct viewing angle for the IP camera | Cabling Point

We often come across focal length in millimeters associated with CCTV Cameras . Most commonly used figure is 2.8mm. This value refers to the distance between the camera lens and the image sensor. Why is it important when selecting the right surveillance camera ? Focal length directly co-relates to the viewing angle of the camera. Here are the commonly used focal lengths and the associated viewing angles of IP Cameras

2.8mm = 90° viewing angle
4mm = 60° viewing angle
6mm = 45° viewing angle
12mm = 25° viewing angle

Most people assume that 90° angle is the best selection because it gives the highest angle of viewing . What is the catch ? Because wide angle lenses cover a large area they make the objects appear small. Therefor in areas where you need to identify small objects such as vehicle number plates
IP camera with 90° viewing angle may not be the best choice.

In most indoor IP camera applications 2.8mm cameras can be used . However for outdoor applications , IP cameras with smaller viewing angles can be used . Each application is unique. Surveillance cameras with narrow viewing angles provides a smaller area of coverage. Which means you need to install more narrow angle IP cameras to get the same viewing area with IP cameras that have wide viewing angles.