The function of the lens is to focus on the camera's sensor (CCD or CMOS) by collecting the reflected light from the scene that the camera is looking at. In most surveillance applications, fixed-focus lenses can be used that provide a fixed perspective. Fixed focus lenses are more economical than adjustable lenses. This calculation tool is useful for calculating the required lens using a fixed-focus lens or by entering the viewpoint or the size of the area to be seen. Especially in long distance applications, "What is seen if a few mm lens is taken?" The answer to the question can be created with this calculation tool. In license plate recognition applications, it is possible to calculate how much area the camera will see and whether or not the license plate of a car passing through that area can be seen.

You can download Hanwha Techwin's field of view calculator software (windows) from the link below.

Version:

Field Of View Calculator V 4.10 (Full)

Field Of View Calculator V 4.10 (Lite)

 

Release notes: FoV (Field Of View) Calculator ReleaseNote

 

How can you use this tool?

This handy tool will help you determine the right lens. Enter the size of the camera's CMOS sensor or select the camera model. Type the distance of the object you want to see in the corresponding field (1 feet = 0.3048m). Enter the focal length of your lens (in mm). The width and length of the image to be taken from that distance will be given to you in the measurement unit you have chosen.

 
   
   
   
   
   
 
  

How do I read the license plate?

To read the plates, the image of the plate should cover an area of 500 pixels or more on the overall image. An example for calculating; Let's assume that our recorder records 352x288 pixels. In total, we have 101.376 pixels. Considering that our plate needs to cover an area of 500 pixels or more to be read 500 / 101.376 = 0.005. In other words, it should cover an area of five thousandths so that we can read the letters in that image. For example; For a vehicle passing 10m away, the area of the license plate / total stage should be 5/1000. The average plate (11x52cm) is 572cm². So the area we need to see at 10 meters is 572x1000 / 5 = 114.400cm² = 11.40m². This area should be approximately 3m from 4 lengths. So the lens we choose should be such a lens that it will show us an area of 4x3m at 10 meters.