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Camera Lens

Introduction
Lens are the most important component of CCTV Cameras, typical lens varied with Focal Length, Aperture and Angle of the Field of view. Selecting the appropriate lens is the critical step in constructing a complete surveillance system.

Focal Length and Angle of the Field of View
Lens with a shorter focal length monitor a nearer object more clear than that with longer focal length. In contrast, lens with longer focal length can take a more distinct image than that with shorter focal length. However, the angle of the Field of View is greater with a short focal length and will show a wider picture. The angle of the Field of View is smaller with a long focal length and will show a narrower picture. Here are the example of lens with different focal length.
 

Camera Lens

Adjustment of Aperture
As CCTV Lens do not like human eyes, they need appropriate aperture size to take optimum light level for the exposure of image. There are three kinds of lens available: Fixed Manual monofocal lens, Manual monofocal lens, and Auto iris monofocal lens.

Basic CCTV Lens

 Model
 Type Fixed iris
monofocal lens
Manual Iris
monofocal lens
Auto Iris
monofocal lens
 Introduction - Iris control is fixed
- Widely used for indoor
   purposes
- Inexpensive

 
- Manual adjustment
   needed for iris control
- Widely used for indoor
   purposes
- Little expensive than
   Fixed one
 
- Adjustment of iris is
  automatic
- Widely used for in/out
  door purposes
- More expensive than
  Fixed one
 Focal Length Selection 2.8/4/6/8/12/16/25 mm 2.8/4/6/8/12/16/25 mm 2.8/4/6/8/12/16/25 mm
 Mount CS Mount CS Mount CS Mount
 Adjustment Focal Length Focal Length/iris Focal Length
 Warranty 1 Year 1 Year 1 Year
 

Advanced Camera Lens

 Model
 Type Fixed iris
monofocal lens
Manual
Varifocal lens
Motorized
Varifocal lens
 Introduction - Automatically switch to
  IR under low light
  conditions
- Widely used for indoor
   purposes

 
- Manual adjustment
   needed for iris and
   varifocal length control
- Widely used for indoor
   purposes
 
- Adjustment of iris and
  focal length is
  automatic
- Widely used for in/out
  door purposes
- Expensive
 Focal Length Selection 2.8/4/6/8/12/16/25 mm 3.5-8 mm/
5.5-33 mm
3.5-8 mm/
5.5-33 mm
 Mount CS Mount CS Mount CS Mount
 Adjustment Focal Length Focal Length/iris Auto
 Warranty 1 Year 1 Year 1 Year

For More Information
 - Professional Color CCTV Camera Datasheet
 

     
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