Why do 6500K 80CRI LEDs have better rendition of Neutral WHITE compared to 6500K 90+CRI LEDs which appear Greenish-Yellow White?
Not necessarily, greenish-yellow means positive duv. If you dedome 519A you get 90+ CRI with negative duv (rosy). Even regular 519A is 90+ CRI and not greenish, it is close to 0 duv (neutral tint).
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They don’t. You asked the same in your other post and the answer still is: every LED is different.
If you want an LED that is perfectly neutral white you need to go shopping the right type of LED with the right binning (some dealers offer that, most don’t).
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Green is more efficient than White in terms of lumens/W within all else equal. Since high CRI LEDS are not as bright as their lower CRI counterparts, I suspect manufacturers like Cree try their best to make the 90 CRI as bright as possible, and this translates to having more green and a non neutral tint. Nichia on the other hand strives to deliver the best quality light and is willing to forego some lumens as a result. Their 90CRI and even 98 CRI Leds are just as good as their 80 CRI equivalents with respect to tint.
The other thing about tint is that we can usually tolerate a slightly greenish tint (above BBL) at cooler CCT. At warmer CCT’s, a green tint make the light quality a lot worse, and most usually prefer a slightly rosy tint (below BBL). Since many high CRI leds are often only offered in warm CCT’s (ex: Luminus SST20), you may perceive the tint to be more yellow/green than in an equivalent 5000K or 6500K 80 or 70 CRI led that has an equal amount of green in it.
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Your sample size is way too small to come up with that conclusion. Yes high CRI formula has more green / deep-red phosphor instead of just yellow and it shows in the spectrum. However the ratio of R/G/B is independent of the fullness of the spectrum. There are many examples of low-CRI lights that are very green and high-CRI lights that are rosy.
In fact being too green or too rosy will lower the CRI score so by definition a high CRI light can’t be too green unless it is cheating on the CRI score.
The 97CRI+ 519A LEDs in the Convoy S21E and Acebeam E75 have a perfectly neutral tint.
i’ve been testing 6500K leds at three different CRIs, 70, 80 and 95. i find that the higher the CRI the higher is also the yellowish-greenish tint on the LED.
CRI 70 - has very muted yellow-green tint and appears bluish-magenta white
CRI 80 - has better yellows and green compared to CRI70 but still very good white with no bias on yellow and green
CRI 90 - appears more yellowish green compared to CRI80 and is heavily tinted with yellow and green color.
What’s are the LEDs/part numbers for the samples you’ve tested?
Are these observations by eye or using a tool?
Are all LEDs the same CCT?
used my Eye and Opple, all leds have the same CCT at 6500K
70CRI is a i think everlight chip
80CRI is a Bridgelux chip
90+CRI is Luminus
No, it’s not like that. Every LED is different. Every manufacturer is different.
You’re drawing conclusions from a way too small sample size.
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How can you conclude that it’s 90+ CRI that’s causing the greeness not the Luminus brand?
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because another high CRI led that i have is Bridgelux, same situation more yellowish-green.
Not the Nichia 519A.
thanks for the info, i will consider the Nichia 519A in my next build
Color temperature, tint, and CRI, are 3 different variables.
A 2700K +duv LED can look lemon-yellow but still be high-CRI. And conversely, a low-CRI LED can look beautiful.
Said it before and I’ll say it again, the 4C XM-Ls in old Convoys and the like, look like shiite behind a reflector, with a nasty-ass fried-egg beam, but behind a TIR lens that mixes all the colors nicely, it’s a beautiful warm sunlight color. Just warm of neutral, +duv just like real sunlight, and even if you can’t discern robin’s egg blue from baby blue from powder blue, who cares, as it still looks nice.
thanks for the suggestion, i will consider the Nichia 519A for my next build. i am really obsessed about getting neutral whites @6500K.
Try the Nichia B35AM, it is available in 6500k and ultra high-cri, I have some and they’re incredible.
If you’re not going for power, the Nichia Optisolis 757 would be better, the color rendering is even higher.
this thread was originally intended for 6500K 80CRI vs. 6500K 90+CRI. it is just my observation that for Cool Whites @6500K, 80CRI has better rendition of Neutral Whites while 90+CRI 6500K appear greenish-yellow.
i am already considering the Nichia Optisolis but price is kind of prohibitive for the very high amount of Lumens that I need 
, so i’m gonna check 519A and your suggestion B35AM
You probably should have made that more clear in your original post. There are very few 90+ CRI LEDs with a CCT cooler than 5700K. The cooler/more blue the CCT, the harder it is for the manufacturer to get decent R numbers across the spectrum. Again, the Nichia 519A at 5700k has an excellent tint, and very “midday sunlight” like light.
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