Guide: How to ensure a stable light color

LED lighting is increasingly replacing alternative light sources such as halogen bulbs and traditional fluorescent tubes. But what standards should you be aware of if you're dealing with LED? Read this week's blog to find out.

Over the past few years, LED lighting has become increasingly popular due to the long lifespan and low power consumption of LEDs. There is also virtually no maintenance associated with LEDs compared to traditional lighting sources, and the color rendering is typically higher for LED luminaires. All of this contributes to the growing preference for LEDs in Denmark.

However, there are several standards and regulations within LED technology that can be useful to look into before you decide to replace your fluorescent or halogen bulbs, for example. These standards cover everything from lifespan to energy efficiency, and more are being added all the time as LED lighting continues to grow in the market. In this blog, we focus exclusively on color stability standards.

Color stability

When dealing with LED lighting, it's crucial to be aware of the different standards and consider which ones are important in a given situation. One of these standards is MacAdam Colour Steps, also known as Standard Deviation of Colour Matching (SDCM). MacAdam indicates the color stability of a light source by measuring fluctuations in color temperature on a scale of 1-10. The smaller the MacAdam ellipse, the harder it is for the human eye to distinguish between color temperatures. Color temperature is measured in Kelvin (K). If the Kelvin value is high, you will experience a cold and bluish light, whereas light with a low Kelvin value is warmer and more yellow or orange.

Things to know about the different MacAdam values

If several light sources are placed side by side, it is important to focus on the MacAdam value of the light sources. With a high SDCM, the light color will vary, so in some cases it may be important to choose light sources with a low MacAdam value.

1 is the best possible value that can be achieved when talking about MacAdam Color Steps. An incandescent bulb typically has a MacAdam of 1, whereas LED luminaires can achieve a maximum MacAdam value of 2. LED light sources with 2-3 SDCM are therefore as stable in light color as possible in LED lighting. With a MacAdam of 2-3, it is therefore difficult, if not impossible, to see a difference in light color.

Hospitals and operating rooms need optimal conditions in terms of color temperature and color recognition. This also applies to museums, galleries, hotels, shops, etc. so it is crucial that the light sources installed here have a low SDCM.

As you move higher on the MacAdam scale, the fluctuations start to increase, but in some situations this is not significant. Indoors, for example, there are higher requirements for a low SDCM than outdoors. Indoors, it is recommended that the MacAdam value is no higher than 3, while a MacAdam of 5 may be more than sufficient for outdoor use.

What does MacAdam mean when it comes to lighting?

An LED module's light color quality, also known as chromaticity, is a measure of the spread of the light color. The dispersion of the light color is expressed in MacAdam and deviations in color are expressed in MacAdam ellipses SDCM (Standard Deviation of Color Matching) according to the CIE 1964 standard. The light color quality or chromaticity is graded via the MacAdam system on a scale of 1-10 - where 1 is the best chromaticity or light color quality you can achieve.

It can be difficult to see differences/deviations in colors between 1 and 3 on the MacAdam scale. However, as you move higher up the scale, the deviations in the colors become more apparent depending on the environment in which the lighting is viewed and assessed. If you are assessing the light color quality of a wall washer or spotlight against a white wall, you will find that it requires a low MacAdam value. Indoor lighting or indoor applications normally have a MacAdam requirement of a maximum of 3 SDCM, whereas outdoor lighting can often make do with 5 SDCM due to the surroundings.

Is light quality even important?

If you experience that the color of a given object you are looking at differs from how the same object would appear in different lighting, it may be because the light quality in the LED module is too poor. Therefore, the MacAdam value should be lower than the rewarding value. Is light quality important at all? The answer lies in the word light quality - it's a choice between good or bad lighting. For example, if you are replacing spotlights, you are faced with the choice of how good the new lighting should be. Light is important for seeing in the dark, light quality is important for seeing everything correctly in the dark. Ask yourself questions like: Do you want to see the white wall white and the green cucumber green? Is it outdoor or indoor lighting that needs to be installed or replaced? What does the surroundings look like? Then choose an LED module with a MacAdam value that fits exactly what your project needs.

What causes the difference in color stability?

There are several reasons why some light sources emit a more unstable light color than others. First and foremost, both the construction and the quality of the materials used in the construction have a significant impact on the final quality of the product and thus also on how stable the light color will be. In addition, the light color is affected by the LED luminaire's surroundings. For example, if the luminaire is mounted outdoors, it is exposed to all kinds of wind and weather, which can reduce color stability in the long run. Similarly, environments with very high temperatures can affect the light color of the luminaire.

Want to know more?

Still not sure which MacAdam value you should be looking for or if MacAdam is even relevant to your project? Then contact us today. Our LED experts are ready to help you.