The CRI value (Color Rendering Index) is supposed to determine the color fidelity of light sources - but it (usually) doesn't!

Why it is important for you to know and understand not only the CRI value, but also what is behind the R9 marking

How do you explain color, and more specifically, how do you explain right color as opposed to wrong color, because that's important when it comes to understanding light and its idiosyncrasies.

Retailers, for example, should consider a few things when choosing the right type of light for the presentation of their products and merchandise - after all, they want the products to look correct and natural in terms of colour and not colourless, dingy subdued or misrepresented in any other way.

The use of artificial light sources such as e.g. LED emitted light has various aspects and characteristics that need to be taken into account.
The CRI or Color Rendering Index is the most common method for evaluating color fidelity. But there's more to understand and consider when it comes to colour rendering and light quality – in this respect, the CRI value of a bulb is not very meaningful on its own.

And that's where R9 comes in. To explain what the R9 illumination value is and why it's so important, let's first clarify what exactly the CRI or Color Rendering Index is.

CRI is a value that measures the ability of a light source to reproduce the accurate, natural colors of an object compared to a reference light source such as sunlight. CRI has a maximum value of 100. Light sources with a high CRI value, e.g. B. 80, 90 or even 100 are best suited to reproduce colors true to life - but...

Fourteen test colors are used for the full CRI, which are evaluated with values ranging from R1 to R14. For each individual color, a high CRI value means that that color is well reproduced. However, the general CRI value used by light source manufacturers only measures a light source by the first eight colors and averages the individual values from R1 to R8.
Another shortcoming here is that these first 8 colors of the test scale only include pastel shades that are easier to represent.

The test colors R9 to R12 are not evaluated, although they are the most saturated colors: red, yellow, green and blue, and R13 and R14 as earth tones. However, since the color red is extremely important for the human eye - from clothing to food to works of art - only a high CRI value, which also includes at least R9 (red), ensures the most vivid and lifelike representation of the actual color and of course all color mixtures that contain red - e.g. ultramarine blue also contains approx. 12-18% red as color bestant. If a lighting is missing the color red or if your CRI for red is low, the ultramarine will appear colder in the direction of a dark turquoise - poor light will lead to the wrong color.



R9 is therefore a very important parameter, which is why the SORAA CRI data always includes R9!

In a restaurant, kitchen, or dining table, you want your food to look its best, fresh, and true to color. Most foods such as fish, fruits, meat and vegetables contain a high proportion of the color red. If the light source directed at these foods does not have a high R9 value, the food will usually appear in the wrong coloring, which is usually unappetizing.

In the same way, you would like e.g. Your objets d'art and paintings appear the way the artist intended, whether they're in a museum, art gallery, or in your home. You always want to make sure that the lighting depicts the artwork in its most accurate, vibrant form, reproducing the full color spectrum as closely as possible.

The same applies to people and the respective different skin tones to a very special degree.

Now you know why you should choose the light or light you need. of your bulbs should pay attention to the R9 specifications.
Our everyday life is full of red tones and other colors that contain significant amounts of red.
A high CRI value, as some manufacturers claim for their products, is almost meaningless if not at least the value for R9
was included.

To represent the color red or However, R9 requires a lot of technical effort for physical reasons.
On the other hand, the relatively precise representation of pastel shades R1 to R8 is easier to achieve and with less sophisticated technology.

However, conventional LEDs only achieve CRI values of just 20-60, especially at R9.

One aspect on the side...

The CRI and its range of test and Test colours are internationally standardised acc. DIN/ISO. In principle, this is a positive development. The downside is that some manufacturers optimize their light sources for the first 8 test colors in order to be able to advertise with a high CRI. We know something similar from computer technology, where graphics card manufacturers adapt their products to certain performance test software, or the automotive industry with its special adaptations to exhaust gas test cycles.

A high CRI value is important, but it alone says nothing about the quality and color fidelity of a light source.

With TM30, there is now a new standard that is much more meaningful than the simple CRI, which SORAA has supported from the very beginning. Read more here...

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