How to choose a CCTV camera lens?
Source: www.mvteamcctv.com
Date: 2015/12/10
Many People don’t know how to choose the lens for CCTV cameras, today, we will guide you on choosing a CCTV Camera lens and some considerations that should be taken into account when doing so.
It is important to understand the angle of the lens. The angle of view depends on the focal.
? The larger focal, the narrower view angle.
? The sensor of camera (h×v ):
1” sensor: 9.6mmx12.8mm
2/3” sensor: 6.6mmx8.8mm
1/2” sensor: 4.8mm X 6.4mm
1/3” sensor: 3.6mm x 4.8mm
1/4’’ sensor: 2.7mm x 3.6mm
Here let us take MVTEAM HD camera for example,there are two kinds of lens Mount M12 and CS,
For the M12 Mount,has fix lens and vari-focal (2.8mm-12mm) for choice ,but for the CS Mount, just have fixed lens from 4mm to 16mm.
? The formula:
F = v X D /V or f = h X D /H
f: the length of focal
H: the height of object
V: the width of object
D: the distance between camera and object
h: the height of the sensor in camera
v: the width of the sensor in camera
Example 1, you want to watch an object 8ft wide (V) at 10 ft(D) with 1/3" camera (v=4.8mm). You need a 6mm focal lens (4.8x10/8).
Example 2, you want to watch an object 8ft wide (V) at 165 ft(D) with 1/3" camera (v=4.8mm). You need a 100mm focal lens (4.8x165/8).
That means the object is displayed by full screen on your VGA monitor.
If you do not know where you like to see, you can choose a varifocal lens, for example
2.8-12mm etc. so that you can adjust the focal to find the best view.
From the following image you will get a clear picture about how to choose a CCTV camera lens.
Namely the smaller lens have a wider angle view,but shorter distance.
The bigger lens has a narrower angle view and can view longer distance
Lens angle and view distance
If you need adjust the view of angle, you need choose a vari-focal lens. Otherwise, you can choose a fixed lens to save money. But if you would like to install a camera in a closed room and you would like to view the whole room,it is better for you to choose the 2.8mm or 3.6mm lens.
By the way,the angle and IR distance of IR leds should also be matched with the cctv camera lens.
Shenzhen MVTEAM Technology Co.,Ltd. is a professional manufacturer and exporter of POE IP Camera,AHD camera,Hybrid DVR etc. with more than 10 years of solid experience on worldwide market, providing a comprehensive range of CCTV products to serve your needs on CCTV Security applications.
If you have any inquiry or technology questions or suggestions about CCTV products,welcome to contact us.