D65 "Video White" and High CRI Flashlights - Mind Blown!

WebHobbit

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Mar 26, 2011
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Rockport, Indiana
This is a cross-post from a thread I started in the Flashlight Sub Reddit:

Like a lot of you here I started out long ago preferring what I perceived as "true white"....Cool White Flashlights that were probably between 5700 & 6500+. Then slowly over the years as I experienced more and more different lights I started preferring Neutral and Warm stuff from 5000k and below. And then a little later still I discovered the joy of High CRI. And now I prefer high CRI and a temp between 2,500 & 5,000k.

But then VERY recently I started reading about computer & TV monitor Bias Lighting. This is where you apply some peel and stick LED strips to the backside of your monitor. This improves how we view color and contrast. Anyway when I went down THAT rabbit hole I quickly discovered that the darling of that particular subject is a bias lighting kit by a company called MediaLight. Their whole deal is their LED strips are a certified 6500k and 98 CRI. I was VERY skeptical at first to ON PURPOSE install ANYTHING that is the dreaded COLD 6500k in my house! But the more I read the more I kept seeing professional colorist and photo/video editors praising this product as the ONLY one that get the D65 spec right. Apparently the movie/TV/video industry decided a long time ago that 6500K "D65 Video White" would be the standard white balance point that all monitors would be calibrated to.

I'm still trying to wrap my head around this. It seems to me that "true white" would be more like 5200k. But anyway I did buy a kit for my monitor and it is surprisingly pleasant (when set down to 10 percent - the lowest setting). It doesn't look blue at all but the wall behind my screen is a pale sea green so that could be a big factor. So my mind is blown. I am left with many questions though. The biggest two are:

Why did they decide on 6500k? And why do we not have ANY flashlight LEDs showing up anywhere that are 90-98 CRI and 6500k....or really high CRI with ANY temp colder than 4500k?
 

staticx57

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High CRI barely sells outside of the enthusiast side of the light segment. Within that small segment most people prefer 4000k, you do the math on why we do not see a ton of non ~4000k High CRI lights. There are some finally lights out that that deviate from that, mostly on the warmer side. Lucky for us, some of the Noctigon lights are starting to use E21A which also comes in a 6500k R9080 binning so you can have your high CRI 6500k if you are willing to mod. Although addressing your very last point 5000k and even 5700k is commercially available without modding.

I have modded a few lights over the year with the E21A, it is fantastic emitter including 6500k R9080. As mentioned above, the Optisolis comes in 6500k high CRI as well, that is also a fantastic emitter. I have a special request Balaton with one in it, fantastic all around.
 
Last edited:

LEDphile

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Mar 8, 2021
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316
The phosphors are available to get very high CRI at cool CCTs, but one takes a pretty big efficiency hit to get there (even relative to a CRI of 90). There's also additional cost for the phosphor, typically due to additional phosphor colors being added to the blend. So the combination of higher cost and lower efficacy makes the really high CRI LEDs a bit of a specialty item. And since most of the applications that are looking for the really high CRI are at lower CCTs, the cool white very high CRI LEDs are even more of a specialty item, and are thus less common in the market. But as noted, they do exist (Nichia has a few, for example).

As far as the choice of 6500K, note that the CCT of daylight changes over the course of the day (from very warm an sunrise and sunset, to rather cooler at noon), and with latitude and weather (overcast sky light is ~10,000K). From the standard defining D65:
[D65] is intended to represent average daylight and has a correlated colour temperature of approximately 6500 K. CIE standard illuminant D65 should be used in all colorimetric calculations requiring representative daylight, unless there are specific reasons for using a different illuminant. Variations in the relative spectral power distribution of daylight are known to occur, particularly in the ultraviolet spectral region, as a function of season, time of day, and geographic location.
— ISO 10526:1999/CIE S005/E-1998, CIE Standard Illuminants for Colorimetry

Preference for a given CCT will also vary with how bright the light is; you may find that (for example) 5000K varies from looking like a "warm" light (e.g. direct sunlight) to looking "cool" (many "daylight" LED bulbs) : https://upload.wikimedia.org/wikipedia/commons/8/8d/Kruithof_curve_2.svg
 

jon_slider

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Joined
Mar 31, 2015
Messages
5,150
thanks for the food for thought on a new topic for me

I think the idea is to use matching sources, the same CCT for the monitor as for the backlight

In the evening, my monitor changes from 6500k to 3000k. (Night Shift).
5nlEu3wl.png


I did a little experimenting with adding backlight to my monitor, while it is at 3000k, and it does seem most pleasant to have a matching 3000k backlight..

same for 6500k monitor setting, it goes best with matching 6500k backlight. Otherwise one source or the other looks too warm or too cool.
 

ma tumba

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Oct 7, 2013
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1,344
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Russia
After multiple tries and errors in the range between 3700 and 6500k I am now sure that the true white is at no less than 6500. I do admit that 4000K is much easier on the eyes, but we are talking white here.

I am looking forward to trying 7000K and cooler tints in 95+ cri
 

cadcoke5

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Jul 6, 2016
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I know this is a somewhat old thread. And the people in the thread probably already know this. But, others reading the thread should know that what people call "white" will vary with the circumstance.

E.g., if you are in a room with candles burning as your only light, your definition of white will be very different from if your room is primarily illuminated by the bluer light coming in from the windows. Your mind redefines white to be the primary color temperature of the dominant light temperature.

That is the purpose of changing the color temperature (dominant wavelength) of a light source placed behind the television.

-Joe
 

cadcoke5

Newly Enlightened
Joined
Jul 6, 2016
Messages
13
I know this is a somewhat old thread. And the people in the thread probably already know this. But, others reading the thread should know that what people call "white" will vary with the circumstance.

E.g., if you are in a room with candles burning as your only light, your definition of white will be very different from if your room is primarily illuminated by the bluer light coming in from the windows. Your mind redefines white to be the primary color temperature of the dominant light temperature.

That is the purpose of changing the color temperature (dominant wavelength) of a light source placed behind the television.

-Joe
 

Flashlightmaster2021

Newly Enlightened
Joined
Oct 18, 2021
Messages
143
Location
USA
This is a cross-post from a thread I started in the Flashlight Sub Reddit:

Like a lot of you here I started out long ago preferring what I perceived as "true white"....Cool White Flashlights that were probably between 5700 & 6500+. Then slowly over the years as I experienced more and more different lights I started preferring Neutral and Warm stuff from 5000k and below. And then a little later still I discovered the joy of High CRI. And now I prefer high CRI and a temp between 2,500 & 5,000k.

But then VERY recently I started reading about computer & TV monitor Bias Lighting. This is where you apply some peel and stick LED strips to the backside of your monitor. This improves how we view color and contrast. Anyway when I went down THAT rabbit hole I quickly discovered that the darling of that particular subject is a bias lighting kit by a company called MediaLight. Their whole deal is their LED strips are a certified 6500k and 98 CRI. I was VERY skeptical at first to ON PURPOSE install ANYTHING that is the dreaded COLD 6500k in my house! But the more I read the more I kept seeing professional colorist and photo/video editors praising this product as the ONLY one that get the D65 spec right. Apparently the movie/TV/video industry decided a long time ago that 6500K "D65 Video White" would be the standard white balance point that all monitors would be calibrated to.

I'm still trying to wrap my head around this. It seems to me that "true white" would be more like 5200k. But anyway I did buy a kit for my monitor and it is surprisingly pleasant (when set down to 10 percent - the lowest setting). It doesn't look blue at all but the wall behind my screen is a pale sea green so that could be a big factor. So my mind is blown. I am left with many questions though. The biggest two are:

Why did they decide on 6500k? And why do we not have ANY flashlight LEDs showing up anywhere that are 90-98 CRI and 6500k....or really high CRI with ANY temp colder than 4500k?
I purchased the

Wurkkos HD15

and it is still on sale $32.99 plus shipping . https://wurkkos.com/products/wurkko...rch-with-power-bank-function?VariantsId=10220








this youtube video does a good job showing the color. I hope this helps.
I like mine alot. and if you dont own a thrunite t1 and t1 and catapult mini you need those flashlights all from thrunite
 

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