Jadak PHOTO RESEARCH A-TAKT V-7HS, User Manual

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Chapter 3
– Theory of Operation
15
Next, spectral correction factors are established using a continuous source with known intensities at each
wavelength. These factors insure that the proper spectral power distribution (SPD) of the target is
determined following a measurement, and that calculated values such as CIE Chromaticity, based on the
measured spectral quantities, are accurately reported. Lastly, a scaling factor (photometric factor) is
applied ensuring the proper photometric levels such as luminance or illuminance are displayed.
Calculations
The corrected spectral data is then used to calculate CIE photometric and colorimetric values including
luminance, CIE 1931 x, y and
1976 u’, v’ chromaticity coordinates, correlated color temperature in Kelvin
and dominant wavelength. Following are some of the basic calculations used to generate photometric
and colorimetric parameters:
FIGURE 8 - CIE 1931 TRISTIMULUS FUNCTIONS