When comparing lighting, it’s inevitable to come across two metrics for color quality, CRI and Ra. Light from LEDs has a variety of properties, and the CRI value is the most common way to interpret color. However, there’s still a lot to know and think about when it comes to color representation and light quality. So what exactly are R12 and R9 in CRI? To learn what R9 and R12 illuminance means and why they matter, check out the following article together.
R9 is particularly important in the colour rendering index (CRI) for several reasons:
Red Importance:
(1)Physiological Reaction: red is an attractive colour that attracts attention and many real emotional reactions from a variety of people.
(2)Cultural significance: Because of the different cultural contexts in different countries, the colour red is given different specific meanings, such as joy, love, danger, etc. They may be opposite meanings, but they all have different meanings.
1. Meaning and significance of R9
- Meaning: R9 indicates the display degree of red light saturation of the lamp. It is a very important indicator and role to measure the red reduction degree of light.
- Important significance: Our human eyes are sensitive to the changes of red, green and blue colors at different levels. Among them, red is the main factor in color reduction. Without red light, the eyes will reflect green and blue, resulting in a narrowing of the color gamut of color reproduction, which will not only make the visual picture monotonous and boring, but also may reduce the quality of light around us.
- Visual relief:Effectively reduce eye fatigue: A good R9 value can reduce eye fatigue caused by low color reproduction, especially when reading or working for a long time.
Psychological comfort: More importantly, better color can make people happy and create a healthier living environment for us.
From the above, we can see that red is very important in our lives and in some of our environments, because it directly affects our perception and feeling of red and other related colors. Especially in those scenes that require highlighting colors and realism, R9 is even more important.
2. The impact of R9 on color reproduction
- Fidelity: The higher the R9 value, the more realistic the red object restored by the light source. This is very important in museums, art galleries, photo studios and other environments with high requirements for color reproduction.
- Visual experience: In the case of sufficient light, using a light source with a high R9 value can give people a richer and more realistic color experience and improve our visual experience. For shops, supermarkets, markets, and flower markets, lighting with a high R9 value is more important for products, as it can provide a higher degree of restoration for the goods.This makes us like it more when buying.
3. Application of R9 in specific situations
- Protecting children’s eyesight: If children study under low R9 index lighting conditions for a long time, their color discrimination ability will be reduced or decreased, and they will gradually develop symptoms such as weak colors and poor discrimination ability. Therefore, when parents choose eye protection lamps for their children, they must pay attention to the R9 value. This is very important!
- Food display: In supermarkets, restaurants and other places, using light sources with high R9 values can make the color of fruits and vegetables and other foods more realistic, which greatly increases consumers’ desire to buy.
- Art display: In museums, art galleries and other occasions, using high R9 lighting can more accurately restore the color of the work, allowing viewers to feel the charm of art more vividly. Enhance the visual effect of the viewer.
4. Industry standards and requirements
- With the development of the lighting industry and the improvement of people’s requirements for lighting quality, the importance of R9 is increasing. Many specifications require that the R9 value of lamps is greater than zero, and even in some high-end applications, the R9 value is required to reach a higher level.
- For example, the national standard requires that the R9 in the color rendering index of children’s reading and writing desk lamps cannot be lower than zero, which is a concrete manifestation of the importance of R9. The requirements of Energy Star and Design Lighting Alliance (DLC) in the United States include the minimum standard of R9.Quality mark: R9 value is an important mark of light source quality. High R9 value usually means higher manufacturing cost, so it is also one of the signs of high-quality products.
In summary, R9 is particularly important in color rendering index because it is directly related to the ability of light source to restore the color of red objects, which in turn affects the overall quality of the lighting environment and people’s visual experience. When choosing lamps, in addition to paying attention to the CRI value, you also need to pay special attention to the value of R9 to meet the needs of specific scenes.
R12 is a special color rendering index in the color rendering index (CRI), which is specifically used to evaluate the color rendering performance of light sources for saturated blue. The following are some detailed explanations on the role and application of R12:
1.What is R12?
- Colour accuracy:The R12 determines whether the light source can accurately replicate saturated blue light. This is important in many situations where blue light is used, because wherever we look we see blue as an element.
- Colour balance.In a comprehensive colour rendering performance evaluation, the R12 helps to ensure that the light source is able to maintain a good colour balance when dealing with blue, which is crucial to the overall quality of colour reproduction.
- Visual comfort:A good R12 value reduces eye fatigue caused by low colour reproduction, especially if you’ve been looking at the image for too long.
2.Application of R12
(1)Commercial Display
○ In retail places, such as the placement area of electronic products such as mobile phones, computers, and electrical appliances, high R12 value lights can better highlight the details of the blue color of the products and increase the visual effect of the products.
(2)Art and Design
In art galleries, museums, and design studios, good R12 values can ensure accurate color reproduction of blue works and exhibits, and can also attract the viewer’s attention more.
(3)Photo and video production:
In studios and studios, lighting with a higher R12 value is the key to ensuring accurate and consistent color of the blue area in the subject.
(4)Medical field.
In medical places such as operating rooms and diagnostic rooms, accurate color reproduction is very important for doctors to observe the patient’s skin condition, blood color, etc., especially blood vessels and tissues related to blue.
(5) Teaching areas and office spaces:
In classrooms, libraries, offices and other places, a good R12 value can improve students’ learning and productivity and reduce visual fatigue.
(6)Home lighting:
In residential areas, especially for residents who like to decorate with blue tones, using a high R12 light source can make the interior decoration and furniture colors more realistic.
The Color Rendering Index (CRI or Ra) is a quantitative measure of the ability of a light source to reproduce the true colour of an object. It is calculated based on the difference between the colour of an object under a light source and the colour of the same object under a reference light source (usually an ideal or near-ideal light source). The following is a general procedure for calculating the colour rendering index.
In fact, Ra is just a symbol in the general CRI formula, but it has been widely used as a synonym for general CRI. CRI is the percentage of realism of an object’s perception under a light source versus its perception under sunlight. a light source with a high CRI has a more realistic representation of colours, and the closer the eye perceives an object to its natural original colours. That is to say, human beings use artificial light to show the natural degree of colour, this realistic colour rendering effect is called CRI, CRI is higher, the more real the colour presented: CRI is lower, the more distorted the colour presented, now you know why you need to look for R9, R12 in the choice of lights. Now you know why you should look for R9 and R12 in your choice of light. Everyday life is full of reds and blues, so it makes sense to use the R9 and R12 values as a standard for lighting.