All about the green/magenta shift

If you are a lighting technician or anyone with photography experience, you have most likely faced issues with green spikes and worked with plus/minus green gels and filters.

Read on to learn about how using our LEDs can completely eliminate the need for this!

Correlated color temperature is one of the most basic properties of a light source that can describe its appearance. We typically refer to a 2700K light source as similar to incandescent, and 5600K as similar to daylight. Generally speaking, the higher the color temperature, the "cooler" or bluer the light looks, and the lower the color temperature, the "warmer" or more orange-yellow the light looks. It is a one-dimensional number that falls on a scale of red-orange-yellow-white-blue-violet.

Chromaticity is often discussed, however, on a two dimensional plane.

Take CCT 5000K as an example. This color temperature is often considered a very neutral, white color. However, not all 5000K correlated color temperature light sources appear the same! 5000K CCT actually is a locus of points that corrrelates to the color temperature of a theoretical black body radiator when heated to 5000K. As we deviate away above the black body line, we begin to see a shift away from this pure white, towards a slight green. Below the black body curve, we see a shift away towards a subtle magenta. This is all while maintaining a correlated color temperature of 5000K. See the diagram below:

Duv measures the derivation from the black body curve. Any value positive (above) shifts towards the green, while any value negative (below) shifts towards magenta.

At present we provide products meeting ANSI standards, ensuring that our LEDs do not provide a green or magenta cast.

                      American National Standards Institute (ANSI)

Nominal CCT1)        Target CCT and tolerance (K)      Target Duv and tolerance

2700 K                        2725 ± 145                         0.000 ± 0.006

3000 K                        3045 ± 175                         0.000 ± 0.006

3500 K                        3465 ± 245                         0.000 ± 0.006

4000 K                        3985 ± 275                         0.001 ± 0.006

4500 K                        4503 ± 243                         0.001 ± 0.006

5000 K                        5028 ± 283                         0.002 ± 0.006

5700 K                        5665 ± 355                         0.002 ± 0.006

6500 K                        6530 ± 510                         0.003 ± 0.006