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Day Night Colour
Infrared Light Emitting Diode (Night Vision) Cameras
Colour Day Night CCTV Security Cameras with
inbuilt Infrared Light Emitting
Diodes "See-in-the-Dark" and produce images when visible
illumination is zero.
At average levels of illumination these CCTV
Cameras produce Colour
images, depending on their sensitivity (Lux) at low
illumination levels and in total darkness the image is
Monochrome.
These CCTV Cameras generally have a
relatively high sensitivity image sensor and
Fixed Iris Lens therefore under high
illumination levels images will be overexposed for the reasons
outlined here, an
exception is
MINI-COL-IR which has a special Wide Dynamic Range
allowing it to cope with higher illumination levels than
ordinary CCTV Cameras.
Ordinary Colour CCTV Cameras are relatively
insensitive to Infrared because they have an IR CUT Filter
between the Lens and Image Sensor, this filter excludes
Infrared radiation with a wavelength greater than ~ 700 nm
that would otherwise adversely affect White Balance, Colour
Rendition and Image Sharpness.
Day / Night Colour CCTV Cameras are
sensitive to Infrared because they either do not have an IR
CUT Filter or utilise a special NOTCH IR CUT Filter that
excludes the wavelengths most harmful to colour quality (720 ~
830 nm) from reaching the Image Sensor.
A Colour CCTV Camera that does not have an
IR CUT Filter usually has
poor colour rendition
characterised by a
Pink-Red
'tint' when the illumination is InfraRed rich,
use of a 'Notch' Filter helps however White
Balance, Colour Rendition and Image Sharpness are
compromised for Infrared sensitivity. (Image Sharpness
can be restored by using a specially designed Lens that
corrects the focus shift between Visible and Infrared)
The IDEAL Day / Night Infrared
Sensitive Colour CCTV Camera would utilise an
Automatic Iris Lens to cope with
high illumination levels and the Lens would also have a large
aperture (low 'F' number) to maximise light transmission when
illumination levels are low * it would also utilise a
Traditional IR CUT Filter when illumination levels are
adequate for Colour and then REMOVE the IR CUT Filter
when levels are low
Dome-DayNite,
Maxi-DayNite,
Dome-D/NiteEx,
Maxi-D/NiteEx &
CCS-IRdnWD have these features and
are recommended for OPTIMUM results - the
ULTIMATE SOLUTION is
AutoCam-dn or
DomePTZ-dn these also have
Automatic-Focus to ensure crisp images under all conditions.
Infrared rich
light sources include Daylight and most Filament type lamps
including common Spot lamps, Tungsten lamps, Halogen lamps,
etc.
The majority of Light emitted from 'Cold'
type sources such as Fluorescent, Mercury Vapour, Sodium
Vapour, etc., is visible, these sources contain little
Infrared energy.
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