Field of view is another important measurement for security camera. Field of view determine the area that a security camera is able to see. Field of view is often referred to as FOV, and describes the invisible cone that extends from the lens of the security camera.
If the field of view of a security camera is too narrow, it wont be able to capture all of the important detail of the area that it is monitoring. However, if the field of view is too wide, the cameras images may become distorted. Therefore, it is important to understand how field of view works based off what each type of security camera can see, so that you purchase the appropriate security camera for the area that is to be monitored.
Security Camera Field of View
Field of view can be measured in three different way. Horizontal field of view measures the area that the security camera sees from left to right. Vertical field of view measure the area of the security camera from top to bottom.
Finally, diagonal field of view measures the distance from one corner of the area that the security camera is viewing to the opposite corner. While the manufacturer often showcases the diagonal field of view for the security camera, it is important to consider the horizontal and vertical measurements, as well. For example, a security camera may have a very wide horizontal field of view, but if the vertical field of view is relatively narrow, it may not be able to view areas that are high above the area that it is monitoring.
Most security cameras has field of views that range from 40 degrees to 180 degrees, and the type of lens that is installed on the security camera will impact the field of view of that camera. The lens that is installed on the security camera will impact the field of view of that security camera. Security cameras that have short focal length (such as 2.8 millimeters) will have wide fields of view.
These types of security cameras are useful for monitoring large areas, such as backyards. Security cameras that have longer focal lengths (such as 4 or 6 millimeters) will have narrower fields of view. These types of security cameras are useful for viewing small areas from a distance.
For instance, a narrow field of view is useful for being able to view a license plate from a distance, but a wide field of view would be more helpful for viewing an entire porch. While many people believe that the wider the field of view of a security camera is, the better, if the field of view is too wide, the images may become distorted. The distance from the security camera, as well as the height of the security camera, can impact the field of view of the security camera.
The further from the security camera that an area is, the wider the field of view that will cover that area. However, the closer to the security camera that an area is, the more detail that can be viewed. For instance, if the security camera is mounted at a height of 9 to 10 feet, it may be able to focus on the feature of individuals faces.
However, if the security camera is mounted 16 feet from the area that is to be monitored, it will miss some of the features of the individuals that are in that monitored area. The fields of view of each security camera should be overlapping with each other. The overlapping fields of view should account for 10 to 20 percent of the security cameras field of view to account for any blind spot in the coverage of those cameras.
There are different types of security cameras, and each type includes different fields of view. For instance, bullet cameras have relatively narrow fields of view, but are used for viewing long areas like driveways. Dome cameras have relatively wide fields of view, and are used for viewing rooms.
Turret cameras allow for adjustments in the angle in which the security camera’s field of view is directed. Door bell cameras have relatively wide fields of view (ultra-wide vertical field of view) that allow for monitoring of packages that may be placed on a porch. Fisheye cameras has a 360 degree field of view.
Thus, one fisheye camera may be able to monitor an entire room rather than four security cameras of the same type. Pan-Tilt-Zoom (PTZ) cameras allow for changes to the field of view of the monitored area by moving the lens of the security camera. However, PTZ security cameras require more power and bandwidth than security cameras of other types.
Blind spots are the area of the security camera that fall outside of the field of view. Most security cameras have blind spots directly underneath the camera and behind any walls. A map of the location of the security cameras and their fields of view should be drawn.
Any entry point into the property should be marked on the map. Based on the map, the security cameras should be placed into each area to account for each entry point and to ensure that the fields of view of the security cameras overlap with each other. If the fields of view do not overlap with each other, there may be a blind spot in which an intruder pass without being captured on any security camera footage.
Finally, you should test each security camera while in different lighting conditions in the area that it will monitor. The field of view and clarity of the field of view may change in the darker areas of time of night when the lights in the monitored area go out.