How do you calculate the focal length of a CCTV camera?

How do you calculate the focal length of a CCTV camera?

A simplified calculation for 1/4-inch CCTV lens can be made using the following formula:

1. W (horizontal width) = (distance) * 3.2 mm / (Lens Focal Length)
2. HorizontalAngle= 2 * arctan(SensorSize/(FocalLenght * 2))
3. Watch Video Tutorial.

What is focal length of CCTV camera?

The focal length (measured in “mm”) of a lens determines how far the camera can see. The most common focal length on security cameras is 3.6mm, which will allow for roughly a 72 degree field of view (FOV described below). This particular focal length works well for residential or small office surveillance applications.

How far can a 3.6 mm lens see?

Camera lenses are measured in mm, the smaller the number the wider the angle of view. 2.8mm or 3.6mm would be considered wide angle….

2.8mm lens 1.5 metres
3.6mm lens 3 metres
6mm lens 5 metres
9mm lens 6 metres
12mm lens 7 metres

How far can a 2.8 mm lens see?

In general a 5MP 2.8mm lens will offer you around 105° field of view and a 5MP 4mm lens will offer you an 87° field of view.

How much area does a CCTV camera cover?

The C-mount cameras come with a detachable lens, which allows users to change it to fit their needs. For instance, the standard CCTV camera lenses can only cover distances between 35 and 40 feet. With C-mount cameras one can use special lenses, which can cover distances beyond 40 feet.

What is the difference between 2.8 mm and 3.6 mm lens?

A 3.6mm lens is designed to provide an approximate 78° field of view and is the perfect camera in most CCTV applications. Most people think that a 3.6mm lens won’t show a large field of view, but as you can see from the below images, there’s not a huge difference between a 2.8mm and 3.6mm lens.

Which is better 2.8 mm or 4mm?

Although it has more clarity at a further distance, the 4mm lens shows a similar scene to the 2.8mm. The main difference is the reduced angle of view which gives the illusion that objects are closer to the camera. A 4mm lens is useful for detection & identification.

How far can a 2mp camera see?

As I mentioned, the 2-megapixel camera provides a maximum width of 24 ft (7.3 m). Since we cut the triangle in half, the opposite side (O) is equal to 12 ft (3.7 m).