What is different between CRI and RA?

CRI and Ra are both used to evaluate the color rendering index of led lamps,but they are not the same value when describe color quality.

 

There are 15 colors in the color rendering index. 15 color names as follow:

R1: Light grayish red

R2: Dark grayish yellow

R3: Strong yellow green

R4: Moderate yellowish green

R5: Light bluish green

R6: Light blue

R7: Light violet

R8: Light reddish purple

R9: Strong red

R10: Strong yellow

R11: Strong green

R12: Strong blue

R13: Light yellowish pink

R14: Moderate olive green

R15:Asian skin

 

CRI, color rendering index is calculated the average value from R1 to R15. It is the world’s widely accepted metric to describe a light source to reproduce true color ability.

The higher CRI of suspended linear led light better color rendering, the lamps is more close to true color.

 

Ra, general CRI is calculated the average value from R1 to R8. Ra is an important value for color rendering of a light source. Compared with CRI, it can only be used as a critical value, can not fully reflect the color rendering of the light source.

 

Therefore, to evaluate the ability of light source, we can not judge only base on general CRI (Ra). In addition, R9 is very important for the skin and good. For special places, we should also need to consider the special color rendering index R9, color fidelity Rf and color saturation Rg.Fox example, at museums and exhibition halls require Ra>95,CRI>95 and R9>90.At DLC5.1 version, there are also specific requirements for color quality and color rendering, according to TM-30-18(IES),Rf>70,Rg>89 or Ra>80,R9>0 is basically require.

 

When choosing led linear light,we usually recommend high CRI and Ra which can ensure true color and protection eyes.