High Quality FOCUSAFE CCTV Camera Lenses!
FOCUSAFE Popular kinds of CCTV Lenses
1. FOCUSAFE Varifocal Lens
A cctv camera lens whose focal length / viewing angle can be manually adjusted to suit the camera view required.Typical Vari Focal lens lengths are: 3-8mm, 3.5-8mm, 2.8-12mm,6-15mm5-50mm,6-60mm,5-100mm
A cctv camera lens whose focal length / viewing angle can be manually adjusted to suit the camera view required.Typical Vari Focal lens lengths are: 3-8mm, 3.5-8mm, 2.8-12mm,6-15mm5-50mm,6-60mm,5-100mm
2. Fixed Iris
Economical choice.It can not adjust the iris to meet the light change.
3. Auto or Manual Iris
For changing light conditions (e.g. cameras positioned outdoors), Auto Iris lenses are needed. If the sun shines on a camera with an auto iris lens, the lens will adjust the amount of light so the picture remains clear.
For indoor use manual iris lenses are sufficient as light levels will not vary too much.
Auto Iris: Video or Direct Drive
The majority of CCTV Cameras will be able to use both types. Video Drive Lenses contain circuitry which converts video signal from the camera into iris control,but it is seldom used now.Direct Drive Lenses require the cctv camera to contain the circuitry
For indoor use manual iris lenses are sufficient as light levels will not vary too much.
Auto Iris: Video or Direct Drive
The majority of CCTV Cameras will be able to use both types. Video Drive Lenses contain circuitry which converts video signal from the camera into iris control,but it is seldom used now.Direct Drive Lenses require the cctv camera to contain the circuitry
4. Zoom Lens
A lens which has variable focal lengths. The image can be 'zoomed' in or out whilst the view of the camera remains in focus.
A lens which has variable focal lengths. The image can be 'zoomed' in or out whilst the view of the camera remains in focus.
CCTV Lens’ Specification:
Focal Length
The Focal Length is measured in mm. As a guide:
a short focal length (e.g. 2.1mm) = a wide angle of view
a long focal length (e.g. 16mm) = a narrow angle of view
the smaller the CCD Chip - the narrower the angle of view
The Focal Length is measured in mm. As a guide:
a short focal length (e.g. 2.1mm) = a wide angle of view
a long focal length (e.g. 16mm) = a narrow angle of view
the smaller the CCD Chip - the narrower the angle of view
Field Of View
The view of the camera - in relation to the angle of view and distance of the object from the lens.
The view of the camera - in relation to the angle of view and distance of the object from the lens.
Iris
Device inside a lens which opens and closes as light conditions change which adjusts the amount of light passed.
Device inside a lens which opens and closes as light conditions change which adjusts the amount of light passed.
Aperture
Aperture is the area of the camera lens that gathers light. The Iris of the cctv lens controls the size of aperture.
Aperture is the area of the camera lens that gathers light. The Iris of the cctv lens controls the size of aperture.
Depth of Field
The Depth of View is the distance within which objects in a picture are in focus.
A large Depth of Field means almost all objects in the Field of View are in focus.
A small Depth of Field means only a small section of the Field of View are in Focus.
The following factors can lead to a greater Depth of Field: Using a Wide Angle Lens High F-Stop, Using an Auto Iris
The Depth of View is the distance within which objects in a picture are in focus.
A large Depth of Field means almost all objects in the Field of View are in focus.
A small Depth of Field means only a small section of the Field of View are in Focus.
The following factors can lead to a greater Depth of Field: Using a Wide Angle Lens High F-Stop, Using an Auto Iris
F Stop
F Stop or Aperture has 2 measurements. When the lens is fully open (Maximum Aperture / Minimum F-Stop), just before the lens completely closes (Minimum Aperture / Maximum F-Stop).
F Stop - is the lenses ability to gather light depending on the aperture and focal length.
F Stop or Aperture has 2 measurements. When the lens is fully open (Maximum Aperture / Minimum F-Stop), just before the lens completely closes (Minimum Aperture / Maximum F-Stop).
F Stop - is the lenses ability to gather light depending on the aperture and focal length.
C or CS Mount
The two standard cctv camera lens mounts. The distance of lens' focus to the chip of camera is different: ccd image sensor. C Mount - 17.5mm CS Mount - 12.5mm
The two standard cctv camera lens mounts. The distance of lens' focus to the chip of camera is different: ccd image sensor. C Mount - 17.5mm CS Mount - 12.5mm
C Mount lenses need an adapter ring when used with CS Mount camera.
CS Mount
More recent type of mounting for CCTV Camera Lenses. Designed for 1/2", 1/3" 1/4" CCD cameras, CS-Mount is the more common lens mount used today in CCTV cameras.
More recent type of mounting for CCTV Camera Lenses. Designed for 1/2", 1/3" 1/4" CCD cameras, CS-Mount is the more common lens mount used today in CCTV cameras.
Usage:
C mount lens can be fixed into C mount camera,CS mount lens can be fixed into CS mount camera;
C mount lens can be fixed into CS mount camera only add a 5mm C/CS lens' adapter ring;
CS mount lens can not be fixed into C mount camera!
