| Most CCTV applications use a fixed-focal-length lens around 3.6mm or 4mm which, like your eye’s lens, covers a constant angular field of view of about 70ish degrees. This is generally a good camera to mount for corner mounting or even just hallway views.
A large variety of CCTV camera lenses are available with different focal lengths, which will provide different fields of view. Wide-angle, medium-angle, or narrow-angle lenses produce different magnifications and fields of view.
This field of view calculator will help you in determining which lens is right for your application. Simply enter the distance to the object, camera format, and focal length of the lens. Click
“Calculate” to see the field of view you can expect with that lens. It also works in reverse. If you know the field of view you need, enter it in and the distance to the object along with camera format
to find the focal length you will need to get the field of view desired.