e pictures taken by a black and white camera are good enough for the surveillance purpose and if there is no other reason to flood with white light the scene to be observed, than a camera that combines a number of infrared illuminators around the lens in a single case can be a convenient solution.

The number of illuminators available

Light is essential for taking pictures. The visual spectrum of light is only a tiny portion of the whole spectrum of radiation that extends in both directions from the edges of the visible rainbow colors.

There is a kind of radiation beyond the red color, called infrared, that is invisible to the human eye. This is the radiation emitted by infrared illuminators used to brighten up a dark scene so that pictures can be taken.

Such illumination would not disturb nocturnal animals in their usual behavior while permitting the study of their habits. The same kind of illumination can also be used to produce clear night vision images for surveillance.

Invisible light of this kind is produced around a well defined wavelength that depends on the type of the emitting diode used. In any case the wavelength is monochromatic, meaning that it has a single "color" (wavelength) even if we cannot see it with our eyes.

Therefore, using infrared light, we will be unable to see the colors of the scene however vivid, because the infrared light used to illuminate it is outside of the visual spectrum.

There are however special devices sensitive to that radiation, in quite normal black and white cameras, that can take the picture and exhibit it on the screen of a closed circuit television as a black and white image for us to see.

If the pictures taken by a black and white camera are good enough for the surveillance purpose and if there is no other reason to flood with white light the scene to be observed, than a camera that combines a number of infrared illuminators around the lens in a single case can be a convenient solution.

The number of illuminators available

ed by infrared illuminators used to brighten up a dark scene so that pictures can be taken.

Such illumination would not disturb nocturnal animals in their usual behavior while permitting the study of their habits. The same kind of illumination can also be used to produce clear night vision images for surveillance.

Invisible light of this kind is produced around a well defined wavelength that depends on the type of the emitting diode used. In any case the wavelength is monochromatic, meaning that it has a single "color" (wavelength) even if we cannot see it with our eyes.

Therefore, using infrared light, we will be unable to see the colors of the scene however vivid, because the infrared light used to illuminate it is outside of the visual spectrum.

There are however special devices sensitive to that radiation, in quite normal black and white cameras, that can take the picture and exhibit it on the screen of a closed circuit television as a black and white image for us to see.

If the pictures taken by a black and white camera are good enough for the surveillance purpose and if there is no other reason to flood with white light the scene to be observed, than a camera that combines a number of infrared illuminators around the lens in a single case can be a convenient solution.

The number of illuminators available

t of this kind is produced around a well defined wavelength that depends on the type of the emitting diode used. In any case the wavelength is monochromatic, meaning that it has a single "color" (wavelength) even if we cannot see it with our eyes.

Therefore, using infrared light, we will be unable to see the colors of the scene however vivid, because the infrared light used to illuminate it is outside of the visual spectrum.

There are however special devices sensitive to that radiation, in quite normal black and white cameras, that can take the picture and exhibit it on the screen of a closed circuit television as a black and white image for us to see.

If the pictures taken by a black and white camera are good enough for the surveillance purpose and if there is no other reason to flood with white light the scene to be observed, than a camera that combines a number of infrared illuminators around the lens in a single case can be a convenient solution.

The number of illuminators available

r vivid, because the infrared light used to illuminate it is outside of the visual spectrum.

There are however special devices sensitive to that radiation, in quite normal black and white cameras, that can take the picture and exhibit it on the screen of a closed circuit television as a black and white image for us to see.

If the pictures taken by a black and white camera are good enough for the surveillance purpose and if there is no other reason to flood with white light the scene to be observed, than a camera that combines a number of infrared illuminators around the lens in a single case can be a convenient solution.

The number of illuminators available

e pictures taken by a black and white camera are good enough for the surveillance purpose and if there is no other reason to flood with white light the scene to be observed, than a camera that combines a number of infrared illuminators around the lens in a single case can be a convenient solution.

The number of illuminators available and their total power should permit to view what is needed in the required detail at the prescribed distance. Therefore the selection shall be based on the objective conditions of the place.

If proper sensors are installed, the illuminators can be turned on only upon detecting movement or other signal starting camera operation. This is the normal way to save on energy expenses and on the service life of the devices.

The secondary gain, possibly even more important, is the saving on the length of tape used for recording and on the time needed for reviewing the footage.

In any case infrared illuminators are the only practical devices that permit to perform home surveillance in the dark, if placing a lamp or a visible light source is not suitable for the situation considered.