Macadam Ellipses: the Variability of Perception, Expressed in Color space

• LED Binning

LEDs can be characterized in multiple ways. For color mixing, the two most important dimensions are color expressed as chromaticity (CCx, CCy), and luminous flux, measured in lumens (lm). These parameters are collected as part of the LED component manufacturing process and are the basis for the component binning discussed in this document.

• Macadam Ellipses: the Variability of Perception, Expressed in Color space

The CIE color space allows an objective way to express color, since no two humans perceive color in exactly the same way. For that matter, an individual’s perception of color varies over time. So how can we come to an acceptably uniform definition of color from the human eye’s perspective?

• Chromaticity Bins

Cree provides industry-leading granularity by defining sub-bins within each of the ANSI C78.377 bins for warm-, neutral- and cool-white XLamp LED products.

• Conclusion

Just like traditional lamps, LEDs are binned for brightness (lumens) and color (chromaticity). Unlike traditional lighting design, LED color mixing can help multi-LED products take the best advantage of LED performance. LED color mixing is an effective technique to achieve consistent, repeatable, multi-LED luminaires. Color mixing also allows the use of a large chromaticity range while reducing LED unit costs and delivering consistent color point results. Cree’s EasyWhite LEDs help simplify luminaire design by mixing colors within the LED component.

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Source: https://www.cree.com/led-components/media/documents/LED_color_mixing.pdf