What Is The Colour Rendering Index (CRI)?

What is the Colour Rendering index (CRI)?

What is the Colour Rendering index (CRI)?

The Colour Rendering Index (CRI) is used to measure how colours look to the human eye under artificial light in comparison to what they look like to the human eye in daylight. If you would like to know more about what daylight is then read here.

CRI is measured up to 100, which is essentially full daylight and is deemed the best quality of light. Daylight style LED bulbs are generally in the mid-80s, meaning they are in the higher levels of the Colour Rendering Index, with anything around 60 being deemed to be low quality (the CRI measurement goes all the way to 0), and not useful for colour matching because this level of light quality will make the colours look unnatural.

What is CRI Ra?

To calculate how the CRI percentage is worked out, a process of CRI Ra needs to be carried out. The percentage gives end users an easy to understand number that can be translated into the bulbs ability to render light in comparison to daylight, with daylight being 100.

CRI Ra (Ra being representative of an average) includes a variation of 14 different low saturated colours across the colour spectrum. For CRI Ra to be calculated only the first eight colours are used to measure an average (Test Colour Samples 01-08).

The last six colours provide additional information about the colour rendering properties of the light that is being measured, with the first four colours being highly saturated and the last two being well-known objects.

What is the Colour Rendering index 2

We supply a range of daylight lamps with CRI values in the mid to late 80s, which ensure you always get a high level of colour matching. In addition to this, many of the lamps have different colour warmth’s which range from 2800K (Kelvins) to 6500K, which is full daylight.
If you would like to know more about stocking our lamps then please get in touch.


Clare Donnelly – Managing Director of Native Lighting Clare has over 15 years of experience working in the lighting sector. She has previously written blogs for the Beauty industry and numerous articles for crafting magazines along with presenting on shopping channels, such as Hochanda.

What Is The Colour Rendering Index (CRI)?
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