Day Night Colour Infrared Light Emitting Diode (Night Vision) Cameras
Colour CCTV Day Night Cameras with inbuilt
Infrared Light Emitting Diodes
"See-in-the-Dark" and produce images when visible illumination is
At average levels of illumination these Cameras produce
Colour images, depending on their
sensitivity (Lux) at low illumination levels and in total darkness the
image is Monochrome.
These Cameras generally have a relatively high
sensitivity image sensor and
Lens therefore under high illumination levels images will be
overexposed for the reasons outlined
Ordinary CCTV Colour 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 Camera that does not have an IR CUT Filter
usually has poor colour
rendition characterised by a
'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 for focus shift between Visible and Infrared)
The IDEAL Day / Night Infrared Sensitive Colour CCTV
Camera utilises a Lens with an
Iris to cope with high illumination levels - has a large aperture
(low 'F' number) to maximise light transmission and is corrected for
Infrared:Visible focus-shift, it also utilises a Traditional IR CUT
Filter when illumination levels are adequate for Colour and REMOVES
the IR CUT Filter when levels are low our
have these features and
are recommended for OPTIMUM results.
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.
capability using a notch (or no) IR-CUT Filter is a trade-off that
adversely affects Colour rendition in "Infrared Rich" environments.