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Illuminator calculation

 Lamp parameters

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Illuminator calculation

 Lamp parameters

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Illuminator calculation

 Lamp parameters

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Lamp parameters are located on the Lamp panel, on the left half of the Illuminator calculation box.

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In case of modeling infra-red illuminator, see IR illuminators.

 

Lamp type

Light efficiency (lm/watt)

Spectral efficiency of radiation

Edit

 

Lamp power (watt)

Light flux emitted by lamp (lm)

 


Lamp  type

 

In the box is necessary to choose lamp type.

 

Lamp type determines:

 

After choosing IR LED in the Lamp type box, units of measure in some boxes will be changed.

See more: IR illuminators.

 

Light efficiency (lm/watt)

 

Light efficiency determines what part of lamp power is converted to visible light. In other words, it is efficiency of the lamp as a source of visible light. Light efficiency is measured in lumens/watts and is given in lamp specifications.

Average value of light efficiency of chosen lamp type is displayed in the box.

 

VideoCAD offers average values of light efficiency for different lamp types. Light efficiency of real lamps can be different. For precise modeling, see lamp specification.

 

For different lamp types the light efficiency is from 8-15 (incandescent lamps) up to 140-180 (sodium lamps) and more lumen/watt.

 

Very often in lamp specifications Power (watt) and Full light flux (lumen) are given instead of the Light efficiency. In this case enter the full light flux value from lamp specification to the Light flux emitted by lamp box.

 

Spectral efficiency of radiation

 

Sensitivity of different types of image sensor to radiation of different wavelengths (spectral sensitivity) essentially differs from human eye spectral sensitivity (and luxmeter sensitivity coinciding with it).

Radiation spectrums of different lamp types can be different.

 

VideoCAD considers this difference through in advance calculated and experimentally verified spectral efficiency factors of different light sources for different types of cameras.

 

During illumination modeling VideoCAD calculates efficiency of each illuminator depending on image sensor type of the active camera.

 

During designing it is not necessary to change these factors.

 

See more: What is spectral efficiency.

 

Edit

 

Edit Light efficiency and Spectral efficiency of chosen lamp type.

 

In VideoCAD the calculated and experimentally verified factors are given. In most cases there is no necessity to change them.

 

The same values of spectral efficiency factors are used in modeling background light in the 3D Video.

 

Lamp power (watt)

 

In the box the power consumption of lamp (watt) is specified.

 

Light flux emitted by lamp (lm)

After specifying the power consumption, the full light flux emitted by the lamp (lumen) will be displayed in the box. The full light flux is calculated from the power consumption and average light efficiency of chosen lamp type.

 

It is recommended to enter in this box value from specification for more precise modeling.

 

 

See also: Illuminator calculation, Luminaire parameters, IR illuminators, Illuminator, Current construction parameter panel>Illuminator, 3D Video>Image parameters panel>Scene.

External link: "The principles of CCTV design in VideoCAD. Part 4. Illumination and camera sensitivity in CCTV"(*.pdf) .