How do I choose the right colour rendering index CRI ?
What is CRI?
The Colour Rendering Index (CRI) indicates how 'real' a light source reproduces colours. In other words: it tells how far colours from a bulb light deviate from the actual colours in daylight.
The Colour Rendering Index has a scale from 0 to 100 percent and is expressed as the Ra value of a light source. With good or excellent colour rendering, no or only minimal deviations in the colour spectrum are visible.
Colour Rendering Index Chart
uYou might be wondering what’s a good colour rendering index? In that case, you will need to consult a colour rendering index table. As you can see in the colour rendering index chart below, a very good colour rendering for LED starts around 80 to 90Ra.
- Ra = 90 – 100 Excellent colour rendering
- Ra = 80 – 90 Good colour rendering
- Ra = 60 – 80 Moderate colour rendering
- Ra = 40 – 60 Poor colour rendering
Poor colour rendering
Moderate colour rendering
Outside lighting, emergency lighting
Good colour rendering
Bureaux, public spaces, industrial areas
Excellent colour rendering
Application booth, showcase
Why is CRI important?
The colour rendering index (CRI) of a light source is a quantitative measure of its ability to reproduce the colours of various objects faithfully in comparison with an ideal or natural light source. In general terms, CRI is a measure of a light source's ability to show object colours "realistically" or "naturally" compared to a familiar reference source, either incandescent light or daylight.
It is significant because it has been the most difficult metric for incandescent replacement light bulbs to match (while maintaining high efficiency) and therefore the most frequently ignored (the CRI spec value appears only on a very small percentage of LED product packaging, For that reason, LED light bulbs with a high CRI can be worthy replacements for incandescent light bulbs. Most LED lights do not have a CRI above 90.
With a good colour display, subtle variations in the colour spectrum are revealed. The Colour Rendering Index (CRI) is a scale of 0 to 100 percent. This index indicates how accurate a light source displays colours are compared to daylight. The higher the CRI, the better the light bulb's display colours. Lamps with a CRI between 80 and 89 have a high colour display. This makes them suitable for almost all applications. Light sources with a CRI higher than 90 have excellent colour reproduction. They are only needed for the most accurate tasks that require an almost perfect colour rendering, such as spray booths and shop windows.
LED lighting and CRI
Anyone who has ever stood under fluorescent lighting may have experienced that a colleague's skin looked very pale. Early fluorescent tubes and the first versions of LED lamps were known for their low CRI levels. Over time, much has changed. Through innovation in the lighting industry, LED bulbs are now not only very economical but can also display bright and accurate colours. With the right LED lighting, you will no longer suffer from colour saturation.
In the video below we explain colour rendering when switching to LED:
What is the difference between colour rendering and colour temperature?
You may now be wondering what the difference is between colour rendering vs. colour temperature. It is important to know that CRI is independent of the colour temperature. The colour temperature creates ambiance but does not affect the colour display. Click here to learn more about colour temperature.
How do I find the colour rendering index for my product?
You can find the colour rendering calculation of your product on the packaging.
If you are buying LED light bulbs at Any-Lamp, then you can find the information about the CRI in the product title or product specifications.
You can recognize the colour rendering of the product by this information:
- Colour Code 930 - Warm White
- Colour Rendering (Ra) 90-99
(Number 8 refers to the colour rendering of 80 Ra and number 30 refers to the colour temperature of 3000 Kelvin).