What is R9?

9 is the the red display ability of CRI, and the bigger the value, the higher the red reducebility. Simply, the higher R9, the better effect of irradiation in fruit, flowers and other occasions, so more vivid. Especially as the main ultra-lighting LED lighting, R9 can not be negative.

The U.S. Energy Star(DLC) for the LED lamps and lanterns of Color Rendering Index R9 not below zero.

Therefore, when we discuss the high CRI LED, not just considering the genaral Ra, but paying more attention to R9, and R9-R12, because the study found the inconsistent problems between LED color evaluation of the general Ra and visual evaluation. Low Ra of LED white light may be not worse in the visual color, on the contrary, high Ra of LED white light is not necessarily better. So only both Ra and R9 have higher value, can it ensure the high CRI of LED.