Moving Forward with Color Rendering for LED’s

We know we’ve talked about CRI in the past, but there is always an advantage to refresh the topic and look at what’s new. Color rendering has changed several times since the original 8 CRI pastel chart that we used int the 1960’s. Since then we have moved forward by adding R9 to CRI to improve accuracy, along with the development of TM-30-15 as a new quality metric to be used and potentially replace CRI-R9.

 

What is CRI? 

CRI is a quantitative measure of a light’s ability to reproduce the color of objects faithfully in comparison with an ideal natural light source, a.k.a. the sun! CRI compares color rendering properties of light sources having the same color temperature. There is a total of 14 colors that CRI compares and takes into account. The problem is that the colors used do not give equal weight to all the wavelengths of light that are visible.

  

 

Why is R9 an important part of CRI?

R9 represents how accurately a light source will reproduce strong red colors (TSC 09), which wasn’t addressed with the original 8 color CRI pastel chart. The “accuracy” is defined as similar to daylight or an incandescent light source, depending on color temperature.

 

Why TM-30-15 should be used more versus CRI.

TM-30-15 is a newer quality metric that was adopted by IES to supplement and potentially replace the old CRI. This new dual metric system provides a measure of fidelity, like CRI does, but calculates it in a completely revised method. It also provides a measure of gamut referencing saturation and vibrancy. As opposed to the 14 Munsell colors used in CRI, TM-30-15 uses 99 color samples from actual objects in our environment that are evenly distributed throughout the wavelengths of visible light. This is what makes TM-30-15 more accurate when determining an LED’s color rendering ability.

 

So, what does this all mean?

A high R9 value translates to a better color rendering result for most applications. That being said, we foresee more CRI-R9 values being labeled on luminaires moving forward. We will also begin to see more and more TM-30-15 color analysis being requested. The ability to accurately predict fixture color rendering is important to users who care about the quality of light. Therefore, it is important to us as your manufacturer and lighting partner.