CRI means color rending index. More the value is, it will make the subject more natural and free. Using in high CRI led makes the subject outstanding in color and features of materials, perfectly reflecting the colors of subject and the human beings. It is an ideal lighting solution for shops and social activities places etc.

Ra is the average from R1 to R8, We should not only take attention on average Ra but also on the situation red special R9 and the average Ra(9-12) of red, yellow, green, blue when design high CRI LED Studies have found that there is gap between the RA and the visual evaluation for the color of the white LED. The color of the white LED with the lower Ra maybe looks beautiful, however the color of the white LED with the higher Ra maybe looks ugly. It can bed ensured the high CRI of white LED when Ra and R9 both on high value. 

R9 refers to a saturated red, with wavelength of 650nm. When the R9<0, the red light is not enough, the red serious distortion, so the lamp can not render in the red color naturally. The number more bigger the conductibility of red is more better. All in all, the R9 more big, the effect on irradiation in fruit and flowers more better, they are more bright-colored. Specially, the product is used for commercial lighting, the R9 can not be negative.