Does Dimming LED Change Spectrum

Does Dimming LED Change Spectrum

We tested HLG 550 ECO 3000K spectrum at 200Watts and 500Watts to see if dimming changes the spectrum. Lamp was operating at the same temperature during both tests. HLG 550 ECO is powered by 1296 pcs Samsung LM301H Full Spectrum White LED.

We measured Correlated Color Temperature CCT, CRI, Red/Blue and Red/Far Red to see if these values changed with dimming

500 Watts 200 Watts
CRI 84 84
CCT 3104K to 3112K 3085K to 3092K
Peak wavelength 609nm 609nm
Red/Blue 3.46 3.51
Red/Far Red 12.27 12.46


Dimming full spectrum white LED has a very small impact on spectrum shift. This impact is so small that it can be ignored for Horticulture application.

There would have been more difference if we would have dimmed down to 10% or lower.

dimming led spectrum change

Measured with Lighting Passport Sensor by AsenseTek