About Ultimate Security

How to use this tool

  1. Enter the distance to the object in the top field.
  2. Enter the imager size of the camera. Enter 1/3" for the image size standard CS mount case camera.
  3. Enter the focal length of the lens. Focal length is the rating of the lens. A typical box style camera lens mount is a 3-12mm. For example, at a 100 foot distance with a 1/3" imager and a 3 mm lens, you will have a horizontal field of view of 160 feet and a vertical field of view of 36 feet.
  4. Click the 'Calculate' button to see the horizontal (width) and the vertical (height) field of view.

How to read license plates

Typically you need a horizontal field of view of 5 to 10 feet or less to be able to read a plate. Thus, at 100 feet with a 1/3" standard camera, you will need a 50mm lens to get a horizontal (width) FOV of under 10 feet. This doubles to a 100mm lens at a distance of 200 feet and so on.

Using only two fields

If you are trying to get a 10 foot Horizontal FOV and you wish to know what size lens you need and know the distance, then erase all of the fields. Enter 10 under horizontal FOV, then enter your distance. Click 'Calculate' and the tool will give you the lens you need.

Supercircuits lens calculator field of view for CCTV cameras and video surveillance

Distance to object (ft.)

Imager Size

Focal Length (mm)

FOV Horizontal (ft.)

FOV Vertical (ft.)

Calculate   Cancel