What is Color Rendering Index (CRI)? What does Ra80 mean?
What is Color Rendering Index (CRI)? What does Ra80 mean?
Color Rendering (also known as CRI):
CRI refers to a light source’s ability to accurately reveal the true colors of object. In the other words, under a certain light, do the colors look natural or correct, as if viewed under natural daylight.
Average Color Rendering Index (Ra):
Ra is one of the most common metrics used to quantify color rendering. It’s a numerical value defined by the International Commission on Illumination (CIE) to evaluate how faithfully a light source reproduces colors. The Ra value is calculated by averaging the rendering results of eight standard test colors (R1 to R8): 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
| Ra value range | Color Rendering Evaluation | Suitable Environments |
| 90-100 | Excellent (High Color Rendering) | Colors appear very natural and accurate. Ideal for environments requiring precise color judgment, such as art galleries, photo studios, medical facilities, and food displays. |
| 80-89 | Above average | Colors look natural enough for daily use. Suitable for general living and commercial spaces such as homes, offices, libraries, and department stores. |
| 60-79 | General | Colors may appear distorted or dull. Suitable for areas where color accuracy is less important, such as warehouses, restrooms, parking lots, and general outdoor lighting. |
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Common Questions
Are the Color Rendering Index (CRI) and the Average Color Rendering Index (Ra) the same?
Not exactly. CRI is a full system used to evaluate the color rendering ability of a light source. It includes multiple indicators, from R1 to R15, and serves more as a concept to describe how accurately a light source can reproduce the true colors of objects. For example, you might say, “This LED light has poor color rendering—it makes everything look gray.” Ra is the average of R1 to R8 within this system and is commonly used as the score to evaluate color rendering performance. So, you could say Ra is a representative indicator within CRI—in other words, Ra is the value used to express CRI."
Why Color Rendering Index (CRI) important?
In simple terms, CRI affects how accurately we perceive colors. It represents a light source’s ability to reproduce the true colors of objects. The higher the CRI, the more natural and realistic things appear. If the CRI is low, colors may look distorted or dull. For example, if a light source has poor color rendering, even a bright red apple might look grayish or slightly yellow. On the other hand, a light source with good color rendering will let you see the object in its true, intended color!
Why is R9 often mentioned in CRI? Why is R9 important?
Ra (the average of R1 to R8) only covers basic, neutral colors. R9, on the other hand, represents saturated red—one of the most critical components in color rendering! R9 is a key indicator for evaluating how well an LED light source can reproduce red tones. The higher the R9 value, the more accurately red colors are rendered. This matters because red is one of the most sensitive colors to the human brain. Many things in our daily lives contain red elements—like human faces, skin tones, lips, blood, meat, flowers, and cosmetics. If the R9 value is low, these things may appear grayish, bluish, or simply unnatural. That’s why in places like fruit displays, flower shops, or fresh meat counters, lighting with a high R9 value is often used to enhance the appearance of red and make products more appealing to customers. So, when choosing lighting, in addition to checking the overall CRI, it’s also important to consider the R9 value.
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↪︎ How to choose the Right Color Temperature (CCT)?
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About Benson Energy Saving Technology
Benson Energy Saving Technology is a professional manufacturer of commercial lighting products and specializes in optoelectronic research and development. We offer ODM and OEM services, as well as commercial, industrial, and office planning design, etc. Feel free to contact us for more information.
We provide a wide range of retrofit led solutions: Semi-industry lighting, Factory lighting, Schools lighting, Office lighting, Library lighting, Machines/Equipment lighting, Commercial lighting/shops lighting, Museum lighting, and other interior lightings or outdoor lightings.
Welcome luminaire manufacturers, lamp designers, interior designers, project engineers, and others who are looking for high-quality retrofit led. Contact us for more business cooperation.
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Explore our product applications
↪︎【CHIMEI Museum lighting maintenance and replaced old luminaires step by step to achieve energy saving target】
↪︎【IKEA Taiwan move forward to convert T5 fluorescent tubes to T5 LED tubes】
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↪︎ How to choose the Right Color Temperature (CCT)?
