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RGBX Spectral Science Color Engine

RGBX SCCE

The R2 & RR fixtures feature a unique color control system called the Quasar Science RGBX Spectral Science Color Engine (RGBX SSCE). It composes target spectral power distributions (SPD) compromised of the component RGBX LEDS of 630nm, 520nm, 450nm, 2000K, and 6000K SPDs. Quasar Alchemy, Quasar Scienceโ€™s internal color science think tank, developed a state-of-the-art set of algorithms that offer a groundbreaking & novel set of color science based concepts first seen in the R2 and RR product lines.

White Light Engine

Saturated Color Control

CIE 1931 xy Chromaticity Control


RGBX SSCE features a groundbreaking set of lighting control concepts that build upon the 1st generation Rainbowโ€™s diode set and base control scheme, as seen mapped within the CIE 1976 uโ€™ vโ€™ Chromaticity diagram below: CIE 1976

RGBX SSCE produces light in a manner similar to digital computer image color control systems by visualizing the chromatic input as a vector in the color gamut created by the Quasar Science RGBX diode set. Users first define a โ€œWhite Pointโ€, the base color of this vector. The vectorโ€™s angle of direction corresponds to a chosen endpoint, ie. the Hue, defined by the RGBX diode setโ€™s color gamut edges. The vector length between base and endpoint corresponds to the Saturation. 0% Saturation means the base, ie the white point, 50% saturation means a halfway blend between the White Point spectrum and the Hue spectrum, and 100% saturation corresponds to the end, ie the pure Hue.


White Light Engine

CIE 1976 RGBX CCT


CCT

The RGBX diode set provides 1750K to 10,000K calibrated SPDs with Spectral Similarity Index (SSI) scores ranging from 61 to 91* when compared to the TM-30-18 reference illuminant SPDs. Quasar Alchemy calculated diode combinations from RGBX for the highest SSI score possible from its diode set for any given CCT

*In-depth information on these subjects can be found in the Technical Specifications section.


+/- Green

Quasar Alchemy also internally developed a new set of +/- Green targets based upon theoretical CC36G and CC30M Wratten filters combined with the TM-30-18 reference illuminant SPDs. Since real filters & gels create undesired CCT shifts while adjusting the green/magenta tint (duv), the RGBX SSCE addresses this problem by maintaining the CCT for +/- Green adjustments.

CIE 1976 RGBX +_-G

Since a portion of the Full Plus Green chromaticity range extends beyond the RGBX LED gamut, Quasar Alchemy also calculated the unreproducible Full Plus Green chromaticity range: 2470K to 1750K. Furthermore, from 1850K to 1750K, no achievable amount of + green adjustment (+ duv values) exists in RGBX, so the engine outputs CCT light values for + G adjustments in this CCT region.

 


Perceptual Threshold Manual Control

CIE 1976 RGBX CCT Perceptual ControlMost lighting fixture digital controls do not provide even color change increments of CCT control throughout the Kelvin range. For example, a 50K increase at 2500K produces a greater noticeable color change than a 50K increase at 5600K.

Instead of allocating too many CCT increments or too few CCT increments by using fixed Kelvin adjustment  increments, Quasar Alchemy allocated the full 1750K to 10,000K CCT control range into 1 Just Noticeable Difference (JND) increments, i.e. a distance of 0.0011on the CIE 1976 uโ€™vโ€™ chromaticity diagram. Each CCT control division therefore yields a consistent chromatic change at the minimum human perceptual threshold. This feature provides the most intuitive CCT control feel versus any other lighting product on the market.


Saturated Color Control

Hue

Sat Color Control HUEThe RGBX SSCE has defined its absolute Hue angles by mapping key points in the RGBX LED gamut to established monochromatic wavelengths for different colors*.

It also has determined the most spectrally accurate mix possible for the RGBX LED diode set between Hue angles 0ยฐ to 120ยฐ.

It then equally divides up each hue between these eight primary and secondary colors to provide the most even amount of saturated hue color control.

*In-depth information on these subjects can be found in the Technical Specifications section.


Hue Intensity Equalization

Hue Int Equalization

Quasar Alchemy created Hue Intensity Equalization (HIE), an advanced under-the-hood calibration feature, to provide the most even exposure of saturated color with respect to the lightโ€™s white point.

As seen in the left figure, the blue diode natively outputs about 4-5 times the amount of spectral energy in the blue region of RGBX SSCE 4300K white light.

This intensity difference cannot be measured by traditional incident or spot light meters. Blue illuminated objects often overexpose or clips in photographic images, especially when lighting effects transition between this saturated hue with others. This overexposure lies at the heart of what is often mistaken for a โ€œcolor gamutโ€ problem

Quasar Alchemy profiled each RGBX diode for its energy in relation to its relevant counterpart in TM-30-18 reference 4300K SPD and wrote a software algorithm in the R2 and RR firmware to automatically adjust any saturated light intensity to its relevant region in 4300K light. Future development and updates will dynamically equalize to the currently set white point

BeforeAftwer Hue Int Equalization


SaturationCIE 1976 Saturation

RGBX SSCE defines saturation as the % mix between an SPD from its white point engine and the absolute Hue angle at the edge of the RGBX LED gamut. 50% saturation describes the halfway point on the CIE 1976 uโ€™vโ€™ diagram between the white point and the Hue.

 

 

 


CIE 1931 xy Chromaticity Control

RGBX SSCE can now take direct CIE 1931 xy chromaticity value input and allows control of its full range of spectral variations for any one of those chromaticity inputs.

CIE 1931 xy Chromacity Control

This input comes currently in the form of DMX control profiles and will soon come via manual entry. The CIE 1931 xy DMX control profiles expect: Channel 1โ€” intensity value in %; Channels 2 & 3โ€” x and y values ranging between 0 to 0.8 scaled to 0% to 100% of the channel value; and Channel 4โ€” Spectrum control value.

The conversion formula for Channels 2 & 3 is (input x or y value)/0.8 = DMX %. For example, a desired coordinate of x = 0.31 and y = 0.31 must be transmitted as 0.31/0.8 = 0.3875, or 38.75% for each channel.

For Channel 4, RGBX SSCE has been calibrated to provide the RGBX diode set's entire range of spectrum possibilities for each point in the entire device's gamut. Please refer to the follow section for further explanation of this novel feature.


Spectrum Control

RGBX SSCE now provides Spectrum Control, a novel color control feature that provides the full range of spectral possibilities for any given color value. Since an infinite array of spectral fingerprints (technically called illuminant metamers) can generate any desired xy or u'v' chromaticity value, R2 and RR devices now have full calibration to provide any possible spectral combination, as seen in the below illustration for 3200K white light:

QS xy Spectrum Control

This function serves both technical and creative purposes. It can either be used to provide any level of spectral quality to match or complement other fixtures in a lighting setup, or it can be used to provide a dynamic creative lighting effect in real time. 

Currently, this function can only be accessed via the CIE 1931 xy chromaticity DMX profile. When chromaticity control is fully integrated into manual control, the Spectrum Control will also be a manual control parameter. 


Parameterized Calibration

Underneath the hood, the RGBX SSCE uses dynamic equations to implement device color calibrations. This software design philosophy creates:

  • Faster updates
  • Faster & more accurate calibration cycles
  • Faster factory batch calibration
  • Speeds refinement of color calibration for the entire CIE1931 xy or CIE 1976 uโ€™vโ€™ map
  • Facilitates 3rd party bluetooth app integration
  • Users will soon be able to custom โ€œtrimโ€ adjust different fixtures and eventually send in their lights for factory recalibration.