 How does an Outside Night Vision Security Camera Work?
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A Night Vision Security Camera uses something called image
enhancement or image intensification. The camera contains a lens that senses light but not in absolute darkness,
where you would need thermal imaging. This requirement isn’t normal in the home or factory situation where there
is usually some light from the street or the building. The camera then converts and magnifies the light photons
through a photocathode which produces a very good image on the camera’s screen.
Night Vision Security Camera infrared illumination and
LED's and Images
When you read descriptions of a night vision security camera and
it uses words like infrared illumination and infrared LED’s [Light Emitting Diode], what this means that the
area is saturated with reflective infrared light, so the night vision security camera gets far greater
detail. It’s similar to shining a spotlight on an object making it far easier to see, and as a result you get
far better and clearer image in the dark.
This means not blurry at all at night, but you won’t get colour.
In fact cameras with infrared image enhancement will give you shades of green. The night vision phosphor
screen you see is deliberately green because that is the best colour for the human eye.
Night Vision Security Camera and Lux
Rating
The Lux rating on a night vision security camera means the minimum
light that the camera can pick up an image, so obviously the lower the Lux rating the better the camera works
at night. A Lux Score of ‘0’ for a night vision security camera is the very top.
Ideally a night vision security camera is aided by infrared LED’s
and should give a Lux score of Zero meaning the security camera can function and give you a good picture in
complete darkness.
Please note a Colour Day and Night Vision Security Camera will
automatically switch to black and white at night to improve the picture, and back to colour in
daylight
What does Night Vision Security Camera ‘Generation’
Mean
Night Vision Technology has been around for a long time and so has
gone through several generations. Initially Generation 0 was the beginning, and it was just an infrared
spotlight and a photosensitive receiver which wasn’t very effective.
Generation 4 is the newest and most advanced, most expensive, and
most powerful, with Generation 3 the one in use by the military with a long life.
To summarise Generation tells you the quality, and be aware that
Night Vision Security Cameras of all generations are still being manufactured and sold. Essentially don’t
waste your money on
Cheap Generation
1.
Night Vision Security Camera Range of
Effectiveness
The range of a Night Vision Security Camera is limited by the
amount of reflected Infra Red[IR] light it can detect. If the camera is more of the thermal imaging/low
wavelength infrared passive reception type it can pick up movement and heat much further away, than it will
if intruder is stationary.
You are looking at effective ranges of between 30 to 300 metres,
but this will be affected by weather conditions, and of course if you increase the infrared illumination of
the area you want covered then this will increase the effective distance.
Power Sources for Night Vision Security Cameras
Either a
wall socket or battery included as well. You will obviously need video and audio cables as well. Wireless models
transmit to a receiver unit which then is attached to the monitor. This type of Night Vision
Security Camera will require an external power source, obviously out of reach of the
intruder!!
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