CCTV (DVR, Security cameras), Spy Surveillance (Hidden cameras, Portable video recorders), GSM Surveillance, Design, Installation
Basket empty

User name:
Password:


Think Surveillance —
 
Think Neo-Surveillance
 

Lenses

Selection of the correct lens type is as important as the camera selection. A poor lens performance can significantly detract from the overall performance of the system.

Below are commonly used CCTV Lens terms.

Focal Length

The "focal length" of a lens is the distance between the optical centre of the lens and the imaging sensor.
Small focal lengths give a wide angle of view, and large focal lengths give a narrow angle of view.

Image Sensor

The image sensor is at the heart of any camera: captures view and converts to electronic signal. Sensor captures image and converts him into electronic signal. CCTV Cameras come in different chip sizes - 1", 2/3", 1/2", 1/3" and 1/4".
The Image Sensor size will affect the angle of view.

Angle of View

Angle of View is the area of a scene that a camera covers or sees. A large angle shows a lot of things very small, and a small angle shows fewer things, but bigger.
The angle of view can be calculated by the focal length of the lens and the size of the image sensor.

 

Quick reference table to find the appropriate lens for a given angle of view (horizontal)

Focal Length Image Sensor Size

1.78mm

2.1mm

2.8mm

3.7mm

6mm

8mm

12mm

16mm

25mm

1/4" 91º 81º 65º 52º 33º 25º 17º 13º
1/3" 107º 98º 81º 66º 44º 33º 23º 17º 11º
1/2" 122º 113º 98º 82º 56º 44º 30º 23º 15º
HOME | PRODUCTS | SERVICES | SUPPORT | Useful...

Website Under Construction...