SpectralLED® RS-7 USER MANUAL
Page 18
1a. Output Pane
Power Level
shows the output power of the currently generated spectrum as a percentage between 0 and the
RS-7’s Soft Limit (see the
SLM
command, section 4.6.19) which represents the maximum possible power that
can be achieved for the current spectrum.
Radiance
(or
Irradiance
)
, Luminance
(or
Illuminance
)
, CCT
(Correlated Color Temperature in degrees Kelvin)
,
and
1931 x,y chromaticity
are also reported.
Centroid
shows the wavelength-weighted average of the combined spectral output power distribution; this can
be configured to alternatively display
Parabolic Peak
wavelength or
Center
wavelength (
2d
). An RS-7 equipped
with the optional Wavelength Monitor System has the additional capability of measuring and reporting the
centroid/peak/center wavelength of a single channel in real time, and this box will continuously be updating
with wavelength information whenever one and only one channel is active.
Note that all of the boxes except Centroid 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 output spectrum 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.
Holding down the SHIFT key
when you press ENTER when typing a new level into any of the
Power Level,
Radiance/Irradiance,
and
Luminance/Illuminance
boxes will cause the RS-7 to
maintain the same chromaticity
at the new power level. This is because LEDs tend to slightly shift in wavelength (change color) as their drive
current is increased or decreased, so this option provides a way to “touch up” the spectrum at the new power
level to keep chromaticity constant. You will see the
CIE 1931 x,y
box change from blue to green when the SHIFT
key is being held down, as an indicator that the chromaticity is to be maintained. This also applies to the Main
Power Level control (
1b
); change it while holding down the SHIFT key will keep the chromaticity constant.
(ASCII Command API reference
CCSx,y
Section 4.4.6,
OUTC
Section 4.5.3)
1b. Main Output Power Level Control
Click and drag this control up or down to change the output power of the current spectrum in real time. Holding
down the SHIFT key while changing this control will cause the RS-7 to maintain the same chromaticity
throughout the output power range (see the comment about
Holding down the SHIFT key
in the box above).
(ASCII Command API reference
OUT
Section 4.5.2,
OUTC
Section 4.5.3)
1c. Individual Channel Power Level Controls
Click and drag these controls up or down to change an individual channel’s power level.
Hover
the mouse
pointer over a control to display the channel’s nominal wavelength and channel number(s). These controls can
be configured to show either absolute channel power levels (0 to maximum possible), or relative power levels
(relative to the channel that is set to the highest level) using the
Abs/Rel
control (
1d
).
(ASCII Command API reference
SCP
Section 4.2.1)
1d. Absolute vs. Relative Channel Output Power Level
When the Main Output Power of the RS-7 is set to very low levels, the individual Channel Power Level controls
(
1c
), if they are showing absolute power levels (between 0 and the maximum possible for each channel), will
barely be moving at all, and their individual contribution to the current Output Spectrum will not be obvious. By