Color render refers to a different spectral light source irradiate to the same color object, presented the characteristics of different color. Usually represent by color rendering index (Ra). The higher the color rendering index, the better the color rendering properties.
The level of light represent object called color rendering, also known as color reproduction extent, high color rendering light source with better color reproduction, and the color is closer to the natural colors, low color rendering light with poor color reproduction, and the color with more deviation.
Principally, artificial light is same with natural light, people’s eyes are able to identify the colors correctly, of course, it’s depending on the location and purpose of the lighting.
CRI is the relationship between object true color and standard light source. The determination of the Ra value is defined in the DIN6169, which 8 colors are compared between standard light source and the testing light source, the smaller color difference indicates that the color of the measured light source color is better.
Light source Ra value is 100 means things appear in its light source are consistent with standard light.
| CRI | Level | General application | |
| 90-100 | 1A | Used in places require accuracy and contrast color. | |
| 80-89 | 1B | Used in places require correct color judgment. | |
| 60-79 | 2 | Used in moderate color rendering places | |
| 40-59 | 3 | Used in places require lower CRI. | |
| 20-39 | 4 | Used in places no specific requirement. |
Here list the CRI (Ra) for the common used Light source:
Incandescent 97
Daylight fluorescent 80-94
White fluorescent 75-85
Warm white fluorescent 80-90
Tungsten halogen lamps 95-99
High-pressure mercury lamp 22-51
High pressure sodium lamp 20-30
Metal halide lamps 60-65
Sodium thallium indium lamp 60-65
The dysprosium lights more than 85
