Color rendering definition, does CCT play a role?

LED Flashlights – General Info
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Color rendering definition, does CCT play a role?

This is a carried over subject of discussion that began in another thread, to prevent a hijack of that thread.

I wrote that NW has better color rendering than CW:

“go outside and beam a CW light into some green trees, shrubbery or other green vegetation, then shine a NW at the same objects, you’ll immediately see the difference and what I mean”

One reply was that “Colour temperature and rendering are unrelated”

I’m not claiming to be an expert on this in any way, not by a longshot, but I know what I see.
If CW is compared to NW (both at the same CRI), what I see is that certain colors (greens, woodgrains) appear more natural under the NW.

“NW has better color rendering than CW”

Maybe the right way to say it is:

“Colors appear to look better under NW compared to CW”

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Is “Color Rendering” a broad term? Do meanings vary?

Color Rendering:

  1. The color appearance of objects under artificial lighting (what I thought it means)
  2. Ability of a light source to show true colors accurately as seen outdoors in sunlight (or is it really this?)

I understand CRI is the measurement of color accuracy

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And I do understand that colors are more accurately rendered with higher CRI lighting, I also realize CW can be high CRI…
(I have a light with 3x Nichia 219C cool white 5700K, Ra=9050)

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I think the warmer/neutral tint “fools” us into certain colors “appearing” to be more accurate. In other words they look better (more true) but may not be an entirely accurate reproduction.

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Maybe this sums it up pretty well:

If I compare my high CRI CW to a low CRI NW the colors appear more accurate under the CW. In comparison colors under the low CRI NW look “yellowish tinted”

But on the other hand….

If I compare a low CRI CW to a low CRI NW the colors appear more accurate under the NW. In comparison colors under the low CRI CW look “bluish tinted”

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Out of all of the available emitters , I still prefer my Nichia 219B .

Maybe I prefer to see the world through rose-colored glasses …

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I have worked with a lot of advertising/marcom campaigns as a director- and thus worked with many creative types. I also enjoyed a few years of serious photography (back when we developed film) in college (where all that was cheap and available to use) :student:

AND… I also am not any kind of expert either; but here are my thoughts on your perception- and to begin… I agree with you.

The thing is, one can measure the MOST bright (or reflective) source of any subject we choose, but it is not so easy to measure the SHADOWS and the other (lesser) reflections and variations that MAY still reside in your subject GIVEN the entire landscape/area you are viewing at any given time.

Furthermore, you can have a certain wavelength dominate your view when you see a SOLID colored object (without texture: which functionally adds shadowing and multiple wavelengths). But add that texture and those variable wavelengths and your subject might not be so easy to identify!

As you probably know by now- I am a hunter and here is a perfect case and point: seeing a deer’s antlers through the trees. IF you could see them as a true solid color (without any shadowing or variation in texture) they would be a LOT easier to find looking through the best binoculars. But they are well designed and they are very hard to see— until you see them— THEN your brain “maps” that wavelength and specific texture.

So, a higher CW light is going to see the most CONTRAST over-all (I think that is the correct description) and so maybe a better way to say it is a CW sees better black and white. But I’d argue (as you here) that to see more of the colors (especially in certain frequency ranges— like green leaves and brown wood), that that the NW is indeed able to better “reflect” those frequencies in more detail than CW- because those colors and their shadows ARE WHAT WE EVOLVED TO SEE IN THE NATURAL LIGHT OF THE SUN. So our brains CAN see more detail in NW. So more detail NW Vs distance CW (where colors fade and it gets more black and white).

Light only works when it has SOMETHING to reflect off off (ok, I’m edging on metaphysical here) :stuck_out_tongue: But if you think it through, our IR and UV lights (for further example) don’t see well in our regular daylight field of view— but when the subject matter is distinctly viewable USING those frequencies—then we will be able to “see them better” given one knows what they are looking for :wink:

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^ worth bumping, and reading more than once.……An original, experiential, thoughtful and we’ll elucidated contribution regarding color temperature.

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Yeah, I had to read it 3 times so far, I’m beginning to understand it now :stuck_out_tongue:

But yes some real “food for thought” there! Thanks Zappaman!

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CRI is relative to temperature. A 1500K incandescent source will have terrible color rendering except for red tones yet 100 CRI as it’s the reference.

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no, CCT does not change CRI

whether a light looks Cool or Warm, depends on the White Balance of the operators brain at the time.

IF the operators brain is adapted to sunlight, then a CW light will seem white, and a NW light will seem warmer (yellowish).

otoh, IF the operators brain is adapted to darkness (takes 30 minutes in the dark), then the CW will seem blueish and the NW will not seem yellowish.

the following photos are from iPhone 8 with Automatic white balance. Notice how their color changes based on what they are being compared to. Remember the camera is changing its white balance in every shot. IF the photos were taken with a camera with a Manual white balance setting, then all the colors would stay the same. (and what those colors would be, would change based on which white balance Color Temperature was being used)







A light will look blueish if it is cooler than the white balance of the brain at that time. And a light will look yellowish if it is at a lower CCT than the brain is adapted to at that time.

CRI is a separate subject
Tint is a separate subject also
The following 3 LEDs are all the same 90+CRI, but their R9 (RED) values are not the same. R9 is not part of the 90CRI calculation. The 3 LEDs also have different tints. The worm has the most neutral Tint, the S1 Mini has the greenest tint, and the sw 45 219b has the most, what would you call that Tint?:slight_smile:
The CCT of each LED is also different, 4000k for the worm, 5500k for the S1 Mini, and 4500k for the sw45

Tint color is plotted above or below the BBL, the black line (most green top left, most magenta bottom right)
Color Temperature of the light plots along the BBL (most orange on right, most blue on left)
CRI is NOT shown on this chart
White balance is along the BBL, can be at any color temperature, and gives rise to the term Neutral Tint, not to be confused with Neutral White (which is a range of Color Temperatures, Warm, Neutral, Cool)

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I’m not a pro on this subject however I have done a fair amount of research on this exact topic. The short answer to your question is, no a neutral white lamp is not neccesarily going to have a better CRI than a cool white lamp. The ultimate example to prove this would be to look at the specs of an xenon short arc lamp. 6000K and a CRI of >98. While having a higher CCT than a NW led an XSA lamp has a much higher CRI than even the highest high-CRI leds currently available.

The main determining factor for high or low CRI is a lamp’s spectral power distribution, or how much of each wavelength light a lamp has. Lights with massive spikes at certain wavelengths or missing other wavelengths will have a worse CRI than a light that is not missing those wavelengths or has massive spikes.

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Thanks guys… FWIW anyway.

And some excellent science following here to consider— I love this place because I LEARN a lot here :+1:

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Wow! BOTH our posts were posted in like the same second imagioX1… :sunglasses:

So in sound reproduction (my area of some expertise as a former recording studio owner), the sought after “glory” of any source is “flat response”— which at face value, means what you record sounds like the source you recorded. Flat response (of a particular instrument/voice/thing recorded) for a multi-track recording is the goal of many engineers. NOT THAT MANY don’t use a bias source (or intentional effects) on a track- MOST do! But the baseline for MOST tracks (instruments) in more classical recordings (for example) is to get a “flat response”.

Your definition of CRI makes a LOT of sense to me, because it seems to be a measurement of BALANCE across the light spectrum- as in the sound spectrum I am describing here. It’s called “flat response” because there is no rise or drop at ANY frequency— thus the recording is tracking the source perfectly— so not up or down, but FLAT (meaning dead on at the exact frequency- in time with the source).

Again… a random correlation here after reading the last few posts.

Balance is in a way, an appreciation for the “whole view” (or whole sound-field in the studio) and it’s not always so easy to identify WHAT is missing exactly; as much as it is to “feel” that (that) “something” IS missing… OR alternatively, too bright (or loud) at a certain frequency.

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CRI is just a calculation that determines what colors will look like at a particular CCT by in ideal light source (black body). A green will look different at 3000k vs 7000k but both can be “correct” for example. We are just used to the sun so we perceive ideal as high noon sunlight CCT.

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Tint is a perpendicular line to CCT

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Again, I stand educated!!!

When I look up to the biggest light source I know of (not the sun, but the galaxy!)… I see black and white. Funny little word eh?

AND… talk about THROW!

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Thank you, could not have said it in so few words!

Reference photo

High CRI LEDs with differing CCT and R9

beam0 wrote: Color rendering definition, does CCT play a role?
jon_slider wrote: no, CCT does not change CRI

I might need to reconsider if what my former self said… should be my final answer…
Is it just White balance that matches better between the Tool and the daylight on a foggy afternoon?:slight_smile:

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No, you should dissociate those two type of measurements of the light. As said before, CRI has nothing to do with CCT.
CRI is based on spectrum of reflectance. A higher CRI means a richer spectrum of reflectance, more “true” colors will bounce back from subjects to a receptor (eye, camera sensor, etc).
We are not talking about the overall tint of a light source or it’s temperature that seems to affect all colors but about its spectrum. Colors are wavelenghts reflected from a light source. The reference is a black body. If another light source lacks wavelenghts, those missing wavelenghts won’t be reflected then some colors will look different because of those missing wavelengths. Hence metamerism.

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^ thanks for the new word.

Metamerism (color), in colorimetry, a perceived matching of the colors that, based on differences in spectral power distribution, do not actually match.

  • Maybe it could be referred to as a natural form of Creative Perceptualization.
    _

More chewing gum for the eyeballs:

Since the question in the OP seems to have been laid to rest, and we have decided to go deliciously sideways (this being a “Democratic” flashlight forum, without a Gestapo), maybe we can tie things together in an Exoteric manner?

Zappaman ended his post with:

“Balance is in a way, an appreciation for the “whole view” (or whole sound-field in the studio) and it’s not always so easy to identify WHAT is missing exactly; as much as it is to “feel” that (that) “something” IS missing… OR alternatively, too bright (or loud) at a certain frequency.”

Then:
Jon_Slider ended his post (venturing perhaps where no known BLF poster has gone before) with:

“Do sounds have colors?”

With his permission, I will offer that he previously mentioned his desire to bring white balance into the current type of discussion.
Zappaman has managed to do it succinctly, to the point, and leaving no room for rebuttal.

As to Jon’s query:

Yes, ‘Esoterics’ insist sounds do have colors.
Borrowing from Confucius, and his observations concerning beauty, sounds do have colors, but not everyone can hear them.
I might add, that not everyone can hear the same tune.

In an ‘Absolutists’ forum, this might lead to….
“Prove it to me, go ahead, make me believe it”

^ …seems more like religion, not intended for those with open minds, a burning desire to learn, evolve, and discover whatever it is that brought them to the quest in the beginning.

Could it be that so many treat the CRI, CCT, R9, white balance, and latent image perception tug of war/interaction as an Exact Science, ignoring the inconvenience of personal, subjective sensory perception?

Not even all Esoterics envision the same color progression of the 7 major Chakras, though related to the a shared design of our Human Energy/Endocrine gland system?
How many different methods of measuring, determining, and presenting CRI, RMS wattage and Daylight White exist?

How many valid observations can be offered regarding an individual’s personal perceptions?
Do those with vision impairment hear the same, do the vision AND hearing impaired feel ‘touch’ the same? Are any of their perceptions less, or more valid?

Ironic that most people in the world who need a ’good flashlight, have none, nor any idea of what it means. Just a bulb and battery, maybe even a switch that still works…? Right?

What happens the first time they see one of HWang’s Meteors?

From my repeated experiences, unless you explain things first, they will not notice the difference between my 2A and 3D, care much, or pay attention for that matter.

Do they instinctively know what they prefer, of course!
Do they all see/prefer the same?

The challenge of pushing the flashrocket envelope to shorter burn times, and fuglier flames is merely another WTF? to them.

Maybe Esoteric FlashHeads like us can remember things we forgot after drinking too much Lumen-Aid.

The first avowed Exoteric I met never had a Guru, claimed if he had been born in India, he would have ended up a Yogi. Thankfully he was never limited in that manner.
He ate 2-3 times a week, mostly meat, living on coffee and cigarettes to keep himself ‘grounded’.
Every waking hour to him was described as “being on Las Vegas Strip at night, with no relief”.

He could see better than anybody I have known.
I wonder if he ever needed a flashlight?

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I agree technically, but have an experiential question

Regarding the 3 hand photos I posted,
I can also see how beam0 could perceive that the warmer LED has better “CRI rendition”

I myself also see that the warmer light appears to have “better CRI rendition”
Is it some factor other than CRI that makes the Tool the better illuminant, closer to foggy afternoon daylight?

can you help illustrate the reason for the difference between the Tool and S1 Mini hand images. Both are “High CRI”.

does the Tool illuminated hand, look more like the foggy afternoon daylight illuminated hand because the Tool 4000k Color Temperature is closer to the daylight photo color temperature (aka white balance?) than the 5500k S1 Mini?

what causes the Tool to illuminate the hand more realistically than the S1 Mini?
is it a difference in CRI, Tint, R9, or just white balance (aka color temperature?) :slight_smile:

Is CRI overrated and misunderstood? Is R9 or white balance a more significant variable in making the Tool appear to be better than the S1 Mini at matching late afternoon foggy daylight?:slight_smile:

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CRI is a match of the colors between the light source being measured and an ideal light source (black body) at the same temperature. It is why both the sun and an incandescent light source has a CRI near 100, even though colors are perceived vastly different.

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So… CRI is related to CCT, but is not affected by CCT. You might say the CCT of a light source is the zero point for measuring the CRI of that source (because CCT is ‘defined’ in a specific way).

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My Cool White ZL CREEns are also the best for hunting and destroying blood sucking mosquitoes…