White vs High CRI

[pinkpanda3310 (Pinky)]

alternative facts :+1:

[raccoon]

@jon_slider

“The “thumbs up” gesture is considered obscene”

I think it is, but only if you say, "Sit and rotate."

[pinkpanda3310 (Pinky)]

In my experience that’s usually associated with a different digit

[Unheard]

So, if one wants to lose weight, cook and eat beneath a low R9 light.

[TIFisher]

@jon_slider

CRI is 14 color bars. CRI Ra is the white bar in the spectrum graph below:

typically when flashlight sellers mention CRI, they only mean the average of the first 8 bars, hence CRI Ra is the actual complete name for that factor

Great explanation. Is there a specific reason R9-R14 are omitted from factoring of CRI Ra?

[jon_slider]

@TIFisher

Is there a specific reason R9-R14 are omitted from factoring of CRI Ra?

I dont know, not privvy to the politics of CRI regulations…

its like the Ansii Lumen specs… based on rules created by vested interests…

Im just glad to have access to R9 info, from a few people here that own expensive spectrometers… so I can make my own determination, beyond MFG CRI Ra specs… And Im glad to have info on which LEDs are 9080 vs 9050…

then there are some, like Zebralight, that have “High CRI” offerings that are even lower than 9050… the CRI Ra and CRI R9 on this sample (on left) was just 8010…

(focus on the Red Bars)
,

imo, very misleading to call that Zebra “High” CRI.

[Muto]

White = Taylor Swift

High CRI = Your choice of Pop Star

[JaredM]

LMAO

[xevious (Gary)]

@spamyak

Consider temperature to be totally independent from CRI. An 1800K sodium vapor street lamp is very slow CRI (notice that you cannot easily distinguish colors by this light) whereas a candle at that same color temperature is very high CRI. Likewise there are (a few) 6500k >90 CRI emitters and many with very poor CRI.

Temperature measures essentially the ratio of yellow-orange to blue light you perceive. CRI measures the rendering of each individual color. This image comparing a high CRI (left) and low CRI (right) light source may help

Warmer color temperatures will have a peak further to the right, cooler will have a peak further to the left. This is independent of the overall shape/smoothness/completeness of the spectrum which is more or less what CRI measures.

Thank you, spamyak! I see now how misconceptions can easily crop up where Hi-CRI is concerned, and that it’s all about color rendering independent of the emitter tint temperature.

[Rayoui]

@jon_slider

But in the RGB mixed light it would look dark and dull, because there’s no yellow light to be reflected back

same thing happens with Red, and this is The BIGGEST difference between Low CRI and High CRI:

things that reflect red, will look Red, only if the LED produces Red, which Low CRI does not

if the light is Low CRI with Negative Red output, then the red object will look brown

You may already know this, but I just want to clear up another common misconception/misnomer. The CRI color bars (R1-R14) do not indicate the intensity of certain wavelengths; they indicate how accurately a measured source will render a specific sample color swatch.

I’ll refer back to my RGB LED measurement. In this example, the R9 is extremely low (–122) because there is far too much red content in the light at the measured CCT. You can see in the vector graphic that this source is super-saturating reds, but this results in an extremely low R9 value.

Typically, though, when we discuss R9 in regards to white LEDs, a low value is usually the result of not having sufficient red phosphor content, thereby desaturating reds (as you pointed out previously).

[pinkpanda3310 (Pinky)]

Thanks Rayoui, I learned’d something Not only does CRI Ra not include 42% of the measurable wavelengths it gives no regard to intensity of each. I get the feeling a simple ‘high CRI’ labelled led is really just a catch phrase and full graphs like you linked is the only way to know what is a good colour rendering led.

[Streamtronics]

@pinkpanda3310

I get the feeling a simple ‘high CRI’ labelled led is really just a catch phrase and full graphs like you linked is the only way to know what is a good colour rendering led.

That's exactly right. I prefer TM30 anyway, it's a much nicer system than CRI, but the industry is now so deep into the CRI hole it'll take forever to transition to a system that makes more sense.

[kennybobby]

thank you Stream, i learned something too.

TM-30-15 (released in 2015) is a new system [versus the CRI of 1974] of several related measures and graphics that can be used together to effectively evaluate and communicate a light source’s color rendering properties. TM-30 does not require additional testing measurements but offer new information and provide supplementing tools to improve the value of color fidelity.

CRI uses only eight color samples to determine fidelity, the TM-30-15 uses 99 color samples. A lighting manufacturer could ‘game’ the CRI system by ensuring that certain peaks of the light source spectra matched one or a few of the eight color samples used in calculating CRI and thus achieve an artificially high CRI value.

Dept of Energy description pdf: TM-30 Fact Sheet

[xevious (Gary)]

@Streamtronics

@pinkpanda3310

I get the feeling a simple ‘high CRI’ labelled led is really just a catch phrase and full graphs like you linked is the only way to know what is a good colour rendering led.

That’s exactly right. I prefer TM30 anyway, it’s a much nicer system than CRI, but the industry is now so deep into the CRI hole it’ll take forever to transition to a system that makes more sense.

Did you say… “CRI hole?”
:laughing: