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China Outdoor Lights|What is R9 in the color rendering index of LED lamps?|Sunshinelux

July 21, 2022

When you walk into a supermarket to make purchases, I believe you must choose vegetables and fruits like the ones above, right? It doesn't look very appetizing. We believe that many people have the above experience. For a supermarket, if the products displayed are not very attractive, then the sales performance is bound to be greatly affected. Today I would like to share with you my experience related to R9.


First of all, let's take a look at what color rendering and color rendering index.


Color rendering: The color rendering ability of a light source to an object is called color rendering, that is, the degree to which the light source presents the natural primary color of an object. If the color appearance of an object under a certain lamp is similar to the color appearance displayed under sunlight, we call this lamp "a lamp with good color rendering (high)". Usually expressed in "color rendering index" (Ra).


Color rendering index: CIE (International Commission on Illumination) stipulates 14 colors, and China adds the skin color of Asian women to 15 colors. Labeled as R1, R2, R3...R14, R15, respectively. Among them, R1~R8 are called typical display index, R9~R15 are called special color rendering index, and Ra is usually referred to as average color rendering index (that is, the average value of R1~R8). So what's the R9 that's not included? What does it mean for color rendering?


What is R9?


The so-called R9 is the display ability of red in the color rendering index of the lamp. The larger the value, the higher the reducibility of red. If the application scene needs to highlight red, you need to use lamps with a higher R9 value, such as selling fruits, flowers, fresh meat and other occasions. However, in fact, there are many lamps on the market that have negative R9 values. Why is this?

Simply put, cost reasons.


In order to make the R9 value above 0, the requirements for the ratio of phosphors, especially the red powder, will be stricter, and the cost and price of the corresponding lamp beads will also be higher. Of course, it is not ruled out that some companies sacrifice the apparent value in order to ensure the light efficiency when they are unwilling to add costs, resulting in a low R9 value.

What is the effect of the level of the R9 color rendering index value?


The red, green and blue cone cells in the human eye have different sensitivities. If there is a lack of red light, the green light and blue light in the human eye will form a cyan image, reducing the color gamut of color reproduction, not only causing lighting scenes. It's dull and uninteresting, and it also affects the quality of the lighting environment. In addition, the use of lighting with high color rendering can improve people's perception of space, while low color rendering can affect the ability to distinguish objects and accurately perceive the surrounding environment.


The importance of R9 is reflected in residential, retail and hotel lighting applications. For example, the higher the R9, the warmer the family atmosphere is; museums, art galleries and other places require a high degree of true reproduction of all colors, and the requirements for Ra and even the entire R1-R15 index are very strict. We say that high color rendering can reflect the patient's true skin color and help the medical team to work effectively.

In terms of outdoor lighting, such as those used for building facade lighting and floodlights for landscape lighting, if the color rendering index is too low, it will seriously reduce the aesthetics of the building or landscape. Imagine Jiangnan Gardens, what will happen if the landscape lighting is not harmonious?


Therefore, there are many specifications that require the R9 value of lamps to be greater than zero. For example, the US Energy Star requires that the R9 in the color rendering index of LED lamps cannot be lower than zero, and WELL requires that the R9 be at least 50.


How to improve the R9 value of lamps?


There are no technical obstacles to improving R9. There are two main methods at present: white light beads plus red powder or red light beads. The common practice is to add red powder, but the price of red powder is relatively much higher. In the environment where the price of packaged devices is getting lower and lower, all companies want to reduce cost pressure as much as possible, reduce red powder to reduce costs, so R9 is mostly negative, which is the current status quo.


Therefore, when we discuss LEDs with high CRI, we should not only consider the general color rendering index Ra, but also pay attention to the special color rendering index R9 for saturated red, and the special color rendering index for four saturated colors such as red, yellow, green, and blue. Color rendering index R9 ~ R12. Because the research found that the general color rendering index Ra has a problem of inconsistency with the visual evaluation of the color rendering of the LED. Generally, the visual color rendering of LED white light with a lower color rendering index Ra may not necessarily be poor. On the contrary, the visual color rendering of LED white light with a higher Ra is not necessarily better. Therefore, the high color rendering of the LED can only be guaranteed when Ra and R9 have high values at the same time.


When helping retail stores to create a comfortable and healthy shopping environment, we discussed with the lighting design and lighting suppliers that several sets of different lamps were used. We would like to share with you that the R9 values of these lamps are all higher than 50, and the R1-R8 values are also higher than 80, it can be said that it is a very high-quality lamp. It is true that the price of these lamps is higher than the conventional ones, but in order to obtain the certification, the retail store owners specially set aside a budget to purchase lamps that meet the requirements during the procurement process, because they are convinced that such a design will bring better quality to customers. shopping experience.


Ningbo Sunshinelux Lighting Co., Ltd. is a manufacturer specializing in the production of 20w led floodlight, led high bay lights 200w, tripod lights led, rechargeable led light with magnetic base, best solar motion flood light, solar led street lamp, street light price.


Sunshinelux as a professional china outdoor lights, china light manufacturers, led torch china, ufo led high bay light manufacturer, solar LED  floodlight factory, china led street lamp in China. please believe that we will provide the best quality, best service, best price, please contact us.


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