ETC Source Four LED Series - Color Rendering Index and Color Quality Scale Ratings; Note about LED Fixtures

1 Installation and User Interface Overview 16
Note About LED Fixtures
All LED sources experience some lessening of light output and some color shift over time.
Source Four LED series fixtures have complex thermal management systems to minimize
these changes. With typical usage, a fixture will still achieve at least 70% of its initial output
after 50,000 hours of use (B50, L70). In individual situations, LEDs will be used for different
durations and different levels. This can eventually lead to minor alterations in color
performance, necessitating slight adjustment to presets, cues, or programs.
All LEDs may exhibit a slight shift in output as they rise to full operating temperature. Source
Four LED series fixtures allow the selection of different power settings in order to balance
the competing requirements of thermal stability and brightness. Depending on the selected
setting, changes in output as fixtures warm up may or may not be visible to the eye.
Color Rendering Index and Color Quality Scale Ratings
Source Four LED series fixtures are evaluated for Color Rendering Index (CRI) and Color
Quality Scale (CQS) performance using measured output spectrum and optimized mix
solutions for a best spectral match to black body sources at 3200K and 5600K. Color fidelity
was also measured. These numbers may fluctuate slightly from fixture to fixture. This is a
normal characteristic of white LEDs, and this kind of variation is highly unlikely to be
apparent in most applications. The performance is the same for all fixture versions.
Source Four LED series luminaires provide excellent color rendering, particularly the color-
mixing versions. A Duv rating of 0.000 indicates that the color mix used was exactly on the
black body line, with no green or magenta tint.
Daylight and Tungsten fixtures use only white-type LEDs at a fixed color temperature in
order to maximize output and efficacy.
Fixture CRI CQS Color Fidelity Duv
Lustr+ Reg at 3200K 84 87 87 0.000
Lustr+ Reg at 5600K 92 92 92 0.000
Studio HD at 3200K 94 95 93 0.000
Studio HD at 5600K 91 87 86 0.000
Tungsten at 3000K 86 86 86 0.001
Daylight at 5600K 71 70 69 0.001