What is the colour rendering index?
The colour rendering index tells us how well an LED lamp displays colours as they really are. The colour rendering index ( CRI) is a number that measures the ability of a light source to reproduce colours compared to a reference light source. The CRI figure is the TOTAL spectral range of all colours (on a scale of 1 to 15).
What is the RA value?
The RA value is a PART of the light produced by a light source. When measuring the light output of a luminaire, the CRI measures all the colour ranges R1 to R15, but the RA value measures only the blue-green range of the luminaire, numbers R1 to R8. It is therefore important to note that if only the RA figure is quoted for a luminaire, it gives no indication of the luminaire's ability to produce warm tones. The ultimate breakthrough of LED luminaires has been hindered, according to critics, by their poor ability to produce the colours of the illuminated object. This manifests itself as bluish or greyish light. Indeed, we often hear talk of pale people and hospital operating theatres in the context of LED lighting. The most difficult thing for an LED circuit to reproduce is the colour red (R=9).
What is the difference between CRI and RA?
RA = R1-R8 (blue-green colours)
CRI = R1-R15 (all colours)
More information on this in our Blog!
Typical CRI requirements
Office lighting
Office lighting should be recommended to have a minimum CRI of 85, but CRI 90 is the minimum in our opinion. In the office we work for long periods of time with concentration and good quality light helps our eyes. Typically 4000K colour temperature.
Video lighting
For video lighting the requirement is for maximum colour rendering and CRI LED 100, but with a minimum CRI of 95. This allows the video camera to capture all colours correctly. Often, video lighting is also colour temperature adjustable.
Photographic lighting
Photographic lighting requires a maximum colour rendering performance and a CRI LED of 100, but a minimum CRI of 95. This allows the camera to capture all colours correctly. Often photographic lighting is also colour temperature adjustable.
Home lighting
Home lighting should be recommended to have a minimum CRI of 85, but CRI 90 is the minimum in our opinion. This is because if you spend a lot of time at home, the light should be as natural as possible, preferably the same colour as in the shop. The colour temperature will vary depending on the room. Often the colour temperature is also adjustable.
Industrial lighting
Office lighting should have a minimum CRI of 70, but as robotics becomes more common, more is required for artificial intelligence to see better. Even in the case of manufacturing, the CRI 90 will increase. Typically 4000K colour temperature.
Colour temperature is different from colour rendering
Colour temperature measures the temperature of white light. A traditional incandescent light bulb is typically 2700K (yellowish), an office light 4000K (white), outdoors in Finland 5500K-11000K (bluish). These are COLOUR TEMPERATURES. So colour temperature is different from colour rendering. So colour temperature is how the eye perceives the colour of light. If a luminaire has good colour rendering it can still produce warm tones in 4000K light even if the light is white.
Good colour rendering means a lot. It's nice to see the right shades when putting on make-up or cooking, or to distinguish what colour clothes or furniture really are. Also, in poor light, people feel apathetic and something seems wrong even when the lights are on.
CRI 100 LED, is there such a thing?
The colour rendering index CRI is expressed as a number on a scale from zero to 100, where 0 = no colour reproduction and 100 = full colour rendering. The CRI can also be negative. The CRI does not indicate the colour of the light, but is indicated by the colour temperature, measured in Kelvin. CRI 100 for an LED is a theoretical maximum, which means that it reproduces all colours. There are many luminaires in the LedStore range that easily exceed CRI 90, but most, e.g. Led strip CRI 95 can be found in the range or even CRI 98. Led spots are all CRI 98, led panels CRI 95, etc..
Lamps with a CRI above 85 are generally perceived as quite natural. Light below CRI 80 is perceived as unnatural or discoloured, or certain objects look strange in the light. The higher the CRI, the more natural the colours appear. In the past, high colour rendering was only the prerogative of professionals and those working with colour, but today high CRI is available for all home lighting at a reasonable price. The weakness of bulk LED luminaires is still poor colour rendering (CRI 60-80), and be careful, as Ra90 can be Cri70, as natural and red tones do not fall within the Ra measurement range. We indicate the correct CRI value on our products!
CRI of LedStore luminaires
LedStore offers new innovations and LED luminaires where features previously only seen in the most expensive products are now available to all. LedStore offers LED luminaires with good colour rendering for everyone - everyday luxury for every home! CRI 90 LED has been a matter of course for us for years and high CRI LED is LedStore's trademark for light quality. We have worked for years to ensure that the LED lights in our range exceed these basic standards for us. Here are the CRI figures for our range:
- LED panels and ceilings CRI 93 - 98
- LED light bulbs CRI 95 - 98
- LED spotlights CRI 95 - 98
- LED strip CRI 95 - 98
- LED track lighting CRI 90
So as you can see CRI 100 LED is practically a big part of our range.
Below is an example of a LedStore LED panel with a very high CRI (colour rendering index). We aim to include measurement results of CRI values for all our luminaires as a downloadable a file.
While this work is in progress , here below is a sample CRI report for our top quality GU10 bulbs. On the bottom left you can see 15 horizontal bars, all close to 100 points. This bulb has a CRI of 98. The colour temperature of the light is 3 076K, which is in the 3000K range.
Colour rendering index CRI, but not the same as Ra number
This category contains practically all our lamps, as we focus on CRI 90+ lamps.