Close this search box.

What is CRI (the color rendering index)?

LED lighting design: how to restore the true color of the object 100%? Grasping the color rendering index is especially important for children, what is CRI?

I believe that friends who pay attention to lighting or lighting design will come into contact with a term called “color rendering index”. What does this mean? Let’s find out together.

Table of Contents

The color rendering index of the light source refers to the parameter of the ability of the light source to restore the color of the object. It is mainly used to define the difference in the chromaticity of the LED light source. The score of this index is 0-100.
Simply put: color rendering is an important aspect of evaluating the quality of lighting, and color rendering index is an important method to evaluate the color rendering of light sources, and an important parameter to measure the color characteristics of artificial light sources. The higher the color rendering index, the higher the color rendering index of the light source. The better the color, the stronger the ability to restore the color of the object.
The Commission Internationale De L′E′clairage (CIE) defines color rendering as: compared with a standard reference light source, the effect of a light source on the color appearance of an object.
General color rendering index: the larger the Ra, the better the color rendering performance; on the contrary, the worse the color rendering performance. The color rendering index of sunlight is defined as 100.
Although the “color rendering index” does not represent all of a lamp. But “high CRI” can largely determine the effect of lighting-high color reproduction.

what is cri

what is CRI

As shown in the figure below: the light source with Ra>90 presents the natural primary color of the object stronger than Ra<80, and is more visually comfortable

CRI compare

Difference for high CRI and low CRI

Let's take a look at the colors and details of the object under different color rendering indexes,​We can see that under the light with a color rendering index above 90, the color of the lotus is richer, the color is fuller, and the details are clearer.

about CRI 7

color rendering index of sunlight

The Commission Internationale De L′E′clairage (CIE) sets the color rendering index of sunlight as 100 and specifies 15 test colors. R1-R15 are used to represent the display index of these 15 colors. When comparing a light source with a specified reference light source, an index value of 100 is the best.

about CRI 2

color reduction levels by the light source

Generally speaking, Ra refers to the average value of the eight natural color reduction levels of R1-R8 by the light source, and R9-R15 is not included in the calculation. But from a professional point of view, to evaluate the light source CRI, the parameters of R9 (redness for red) and R15 (for Asian skin tone) should be considered.

cri and cct

What causes the difference in CRI color rendering index

​ Since the LED lamp is excited by the blue chip to generate white light by the yellow phosphor, it is extremely lacking in the red wave band, which causes the LED lamp to have no red display ability. When we choose LED lamps, we must not only look at the color rendering index Ra, but also the values of R9 and R15. Generally, the color rendering index of lamps and lanterns is recommended to be Ra>90 (R9>50, R15>90).

The difference in color rendering index:

90-100 Places that require precise color contrast, such as museum lights;
80-89 Places that require correct color judgment;
60-79 Places requiring medium color rendering;
40-59 Places with low requirements for color rendering and small color difference;
20-39 Places with no specific requirements for color rendering.

In home lighting design, to create a healthy and good atmosphere, the correct selection of light sources and lamps is particularly important. In order to make the light look better in life, and the colors of food and fruits are more realistic, you need to choose the higher the display index when choosing the lamp, that is, the RA value (R9, R15) must be high.

office desk lighting

If you need a high color rendering index light strip, the first choice is YIFORD’s COB soft light strip​. YIFORD provides soft light strips with a color rendering index higher than 90 for the market. This kind of COB light strip has no bright and dark areas. The brightness is very high, that is, it can be used for lighting or decoration.
What is its specific shape? This 39-second video can take you to understand:


cob led strip lights features

In addition to the advantages of high color rendering index, what characteristics does YIFORD’s COB LED strips have?
Please see the below:
Consistency ,high CRI,flexibility, cuttable,small vloume,thin,dimmable,environmental,save energy,lightweight ,adhesive,waterproof,safety voltage,complete kits,low heat,big angle,variety colors,long life.

cob led strip features 1

If you want to know the specific information of these features, how to use these features to design more creative products or projects, you can read this article:
COB LED Light Strips Most Complete Introduction

COB LED Strips--Best LED Light Strips 2022

The luminous effects of COB light strips and SMD light strips

Compared with traditional SMD soft light strips, COB light strips have no graininess, the density of the lamp beads can almost emit light in a line, and the color consistency is high. It can replace some high-density light strips on the market. COB not only saves costs, but also Solve the problems of graininess, chromatic aberration and easy soldering. YIFORD's COB soft light strip​ can disperse the heat of the chip, improve the light efficiency and improve the glare effect of LED lights.

lighting application

cob led strip lights projects

Many architects and furniture designers use the COB soft light strips produced by YIFORD to create novel and practical projects for your reference.

about CRI 5

best light with high color rendering index

​The national standard stipulates that the color rendering index RA of indoor lighting fixtures is at least 80. From the principle of healthy light consumption, we require the CRI to be greater than 90 when designing and matching products. The best light is natural light, and its color rendering index is defined as 100. At present, the best lamps in the world can only be infinitely close to 100.

Harm of low color rendering index

The color rendering index of the classroom lighting source should not be less than 80. The color rendering index of classroom lighting that is too low affects students’ eyesight to recognize the color of the object, so that the object can not show its true color. If this situation continues, it will cause the decline and decline of color recognition ability, resulting in color blindness and weak color of students. And other serious vision problems and eye diseases.

about CRI 4

The optics community has repeatedly confirmed that natural light can prevent myopia. From the perspective of protecting eyesight, it is the right choice to choose high color rendering index lamps, especially table lamps for children. Children’s books and toys are all colorful. If you choose a table lamp with a low color rendering index, the colors reflected back to the children’s eyes will lose saturation, resulting in color distortion, which is easy to cause visual fatigue, and may lead to myopia.
Therefore, choosing high-CRI lamps is often good for light perception and eyesight.

Summary: Why choose high CRI?

1. High color reproduction: high color saturation.
2. Prevent myopia.
3. It can meet the needs of users.
Solve the user’s pain point: things are not real under the light, and protect children’s eyesight.

Let’s Collaborate
We’d love to hear from you
What is CRI and Why Choose it Important | Understanding CRI