SpectralLED® RS-7 USER MANUAL
Page 29
The value displayed in this box is used to scale the entire Target Spectrum (
3a
) up or down. Click in the box, type
in a new number, and press ENTER to scale the Target Spectrum up or down as desired. The final Target
Spectrum (
3a
) is the combination of the Base Target Spectrum (
3g
) multiplied by the Target Spectrum Scale
Factor (
3h
) multiplied by an Illuminant (
3i
).
3i. Illuminant
Click on the down-arrow and select from the list of CIE Standard Illuminants. The final Target Spectrum (
3a
) is
the combination of the Base Target Spectrum (
3g
) multiplied by the Target Spectrum Scale Factor (
3h
) multiplied
by an Illuminant (
3i
). Note that “Select Illuminant” and “Illuminant E/none” are equivalent (1.0 at every
wavelength, meaning no illuminant is being applied).
3j. Target Spectrum Radiance/Irradiance, Luminance/Illuminance, Correlated Color Temperature (CCT), and
CIE 1931 x,y Chromaticity
In addition to displaying these various measures of the current Target Spectrum (
3a
),
all of the boxes can accept
input
, by clicking on the box, typing in a new value, and pressing ENTER. Changing the
CCT
(Correlated Color
Temperature) or the
CIE 1931 x,y
chromaticity will modify the Base Target Spectrum (
3g
) to match the specified
chromaticity using a color-matching algorithm that uses the tristimulus curves as weighting functions to add or
remove energy in the three X, Y, and Z regions to arrive at the new chromaticity.
3k. Fit To Target Spectrum
This will perform a least-squares-fit match of the various RS-7 color channels with the current Target Spectrum
(
3a
). Note that if the Correct Chromaticity After Fit checkbox is checked (
3m
), the spectrum will undergo an
additional operation after the fit, in which energy will be added or removed using the three Tristimulus curves
(X, Y, and Z) as weighting functions in order to obtain the same chromaticity as the Target Spectrum (this will
necessarily worsen the least-squares-fit spectral match to a small degree but guarantees a perfect colorimetric
match).
3l. Fit At Max
This will perform the least-squares-fit spectral matching to the Target Spectrum (
3a
) with the additional effect of
adjusting the Target Spectrum Scale Factor (
3h
) such that the RS-7 will output the resultant spectrum at the
maximum possible output power level as defined by the unit’s currently configured Soft Limit (see the
SLM
command, Section 4.6.19). Note that if the Correct Chromaticity After Fit checkbox is checked (
3m
), the
spectrum will undergo an additional operation after the fit, in which energy will be added or removed using the
three Tristimulus curves (X, Y, and Z) as weighting functions in order to obtain the same chromaticity as the
Target Spectrum (this will necessarily worsen the least-squares-fit spectral match to a small degree but
guarantees a perfect colorimetric match).
3m. Correct Chromaticity After Fit
When the RS-7 performs a least-squares-fit spectral match of the various color channels to the Target Spectrum
(
3a
), the resultant spectrum is the best possible fit of the RS-7’s color channels to the Target Spectrum
spectrally
, however, this is no guarantee that the final chromaticity of the Output Spectrum matches that of the
Target Spectrum as well. By checking this box (
3m
), an additional operation is always performed after the least-
squares-fit in which energy will be added or removed using the three Tristimulus curves (X, Y, and Z) as