Light Bulb CRI_Grades

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Joshk
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Light Bulb CRI_Grades

Here’s a list of light bulbs, sorted by CRI_Grades. The bold are light bulbs you could use in your home. The CRI_Grade is meant to be read just like a school test score.

This grade is calculated by a math formula. I’m really loving the grade results vs what I think about them after reviewing all the color data from my spectrometer.

And my God, those SunLike are the only LED technology to earn an A grade. Not only that, the SOL model beat the sun itself Big Smile (If you are wondering how, the sun’s not so perfect after it comes through the atmosphere.)

Download my spreadsheet here

I’d like to grade some bulbs you guys have found online and sort them into the table! All I need are the CRI numbers. Thanks!

Edited by: Joshk on 11/29/2019 - 19:45
RobertB
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I put 3000k Soraa PAR30’s in my kitchen. Fantastic lights

Joshk
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I wasn’t able to find the CRI data for those. But Ra and R9 are stated to be 95. That would seem like a good start, but by looking at the TM-30 diagram, it seems other colors are lacking.
But if you like them they can’t be too bad.

rngwn
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Would you mind elaborate how you classify the grades from A – F?

In my book:

I will give most R8000 lights a ‘D’ (plus/minus depending on tints), the bare minimum people should ever be consider using. Obviously R70 and below will invariably get a big fat ‘F’ from me (with a muffled “eww”).

R9050 will be given a ‘C’, the bare minimum I will seek out to use for myself if they are cheap.

Royal Blue” based R9080s will be given a ‘B’, an upgrade over R9050 but the blue peak and the violet/cyan intensity gap still concerns me a bit.

The likes of SunLike/Optisolis will get a solid ‘A’ from me.

 

Searching for High CRI leds since 2010...

 

Has finally gotten to the bottom after 10 years of delving deep into that rabbit hole of them high CRI lights...

 

High CRI, high quality lights doesn't need to be expensive, or is it?

 

RobertB
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Joshk wrote:
I wasn’t able to find the CRI data for those. But Ra and R9 are stated to be 95. That would seem like a good start, but by looking at the TM-30 diagram, it seems other colors are lacking. But if you like them they can’t be too bad.

Did you open the LM79 test report? And where did you buy the Sunlike bulbs?

Joshk
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rngwn wrote:
Would you mind elaborate how you classify the grades from A – F?

In my book:

I will give most R8000 lights a ‘D’ (plus/minus depending on tints), the bare minimum people should ever be consider using. Obviously R70 and below will invariably get a big fat ‘F’ from me (with a muffled “eww”).

R9050 will be given a ‘C’, the bare minimum I will seek out to use for myself if they are cheap.

Royal Blue” based R9080s will be given a ‘B’, an upgrade over R9050 but the blue peak and the violet/cyan intensity gap still concerns me a bit.

The likes of SunLike/Optisolis will get a solid ‘A’ from me.

I gave some thought to posting the formula for my grading scale in the OP. It sure isn’t worthy of being a secret or anything, I just didn’t want to debate it. It is quite hard for LEDs to score good on it. For example, the Optisolis E21A running at 2A without a reflector scored a C+ in the OP. I will post the data below. You will see the R9 and R12 were only 80, and I put strong emphasis on them. So this would be a R9080, scoring a C+.

Quote:
Date Saved,9/14/2019 9:23:38 PM
Title,E21 2A 0_01_6134K

Measuring Mode,Ambient
Color Space / White Point,HSI,D65
CCT [K],6134
⊿uv,-0.0088
Illuminance [lx],12200
Illuminance [fc],1140
Reference CCT [K],5500
LB Index [MK⁻¹],19
LB Camera Filter,81
LB Lighting Filter,——-
CC Index,1.1G

CC Camera Filter,CC10G
CC Lighting Filter,R3316 1/4 PLUS G
CRI Ra,93.6
CRI R1,93.1
CRI R2,96.1
CRI R3,90.5
CRI R4,93.0
CRI R5,95.0
CRI R6,91.9
CRI R7,96.1
CRI R8,92.7
CRI R9,80.3
CRI R10,93.3
CRI R11,91.1
CRI R12,80.0
CRI R13,93.9
CRI R14,93.9
CRI R15,89.7
TM-30-15 Rf,90
TM-30-15 Rg,105
SSIt,42
SSId,72
SSI1,70
SSI2,—-
TLCI,97
TLMF,—-
CIE1931 x,0.3210
CIE1931 y,0.3144
Hue,309deg
Saturation,10%

Joshk
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RobertB wrote:
Joshk wrote:
I wasn’t able to find the CRI data for those. But Ra and R9 are stated to be 95. That would seem like a good start, but by looking at the TM-30 diagram, it seems other colors are lacking. But if you like them they can’t be too bad.

Did you open the LM79 test report? And where did you buy the Sunlike bulbs?

I don’t even know what LM79 is. As noted in the OP, the ones that have a * by them were not tested by me.
After seeing this table though, I did place an order for a SunLike bulb. It’s just curiosity for me though, as the 6w cost me $22 for a single bulb. Each room of my house requires 4 or 5 bulbs.
You’ve probably seem me recommending Hyperikon in a few threads. This isn’t because their performance is perfect, it isn’t, it’s because their performance vs price is unbeaten.

Joshk
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Joshk wrote:
So this would be a R9080, scoring a C+.

btw, it’s intentional that a R9080 scores a C+. Compared to what’s possible in the future, CRI=90 and R9=80 is kind of lame.

The_Driver
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You make it sound like it's an objective comparison even though we can't be sure of that.

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Tint is often more important than bare CRI

XPL HI V2-3D is a lot better than some CRI90 green ugly tinted Chinese COB

Also efficiency plays a big role in a rating
there are some CRI80 COB LEDs that have awesome tint and 8500lm from 50W

Joshk
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BLF is so nerdy. Glasses Ok. I’ll discuss my CRI_Grade calculation when I get back to the computer around noon.

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Joshk wrote:
BLF is so nerdy. Glasses Ok. I’ll discuss my CRI_Grade calculation when I get back to the computer around noon.

Would you use a CRI98 light that’s ugly green tinted just because it gets A+?

Joshk
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I’m back.
Ok. So CRI_Grade. The convention of marking “R9080” to mean Ra=90 and R9=80 works pretty good as a judge of CRI quality. With today’s tech, R9 is the hardest to achieve, and that puts it in plain view. However, some manufacturers now know how to trade R12 for R9. This means R12 could be the only one that is super low and go unnoticed. Now, I’m also a believer in simplifying things, so this is what I did…

I marked my readings, for example, R908060 (Ra=90, R9=80, R12=60). Then I just averaged those numbers. In this example, the answer is 76.66. This gives great importance to the weakest areas of LED technology, resulting in a super useful number. But grading still needs to be done, otherwise it’s not simple enough. So I just applied my High School’s grading system. This specifically calls for rounding to the nearest whole number, then categorizing. (Grade table in spreadsheet). So in this example, 77 = D+.

To see the formulas, grading scale, and to play with your own numbers, download my spreadsheet here

Now if you can read a data dump from a spectrometer, this obviously has less information. But as a muggle, this is like having that data dump read for you. And it focuses on the hardest parts of making an LED, so if the manufacturer gets this right, it’s doubtful they could AND would screw anything else up too bad.

Joshk
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It seems on BLF, silence is approval Big Smile

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I was kinda hoping for some reactions after taking the time to compile that post…

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Joshk wrote:
if the manufacturer gets this right, it’s doubtful they could AND would screw anything else up too bad.

Except for Duv and angular tint shift, both of which are extremely important and noticeable.

Edit to add: I don’t think I’ve ever seen bad tint shift in a household bulb because they’re generally quite diffuse, but it’s common in flashlights. Look at the beam from a flip-chip Cree like XP-G3 or XP-L2 in a reflector and see all the rainbow colors.

Duv is harder for companies to keep under control. Because our vision is so sensitive to green light, adding just a bit of green can bump the lumens way up without wrecking CRI, in order to recapture some of the efficiency penalty you normally find with high-CRI LEDs. But doing this also gives the light a green tone (a positive Duv), which deeply annoys a lot of people.

Joshk
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coherent-rambling wrote:
Joshk wrote:
if the manufacturer gets this right, it’s doubtful they could AND would screw anything else up too bad.

Except for Duv and angular tint shift, both of which are extremely important and noticeable.

I don’t want to say CRI_Grade is anything more than a color rendering score… But at these strict of levels, I don’t know of any real life bulbs that would have bad Duv or tint shift while scoring good on CRI_Grade.

staticx57
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Whats the advantage of this over something like CQS or TM-30?

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About CRI rendering: recently, I started to appreciate the newest CRI measuring method, which uses two values to present overall CRI. Rf (fidelity) is very similar in meaning to Ra (I won’t try to research for the differences now), and the other value is Rg (gamut), which tells, that how much the examined light source is greenish/yellowish (values under 100) or rosy (values above 100).

Rf measures as the same as Ra (range 0-100).
Rg measures from (100 minus Rg’) to (100 plus Rg’), where Rg’ = 100 – Rf

I would use a starting formula something like this:
0.7 × (Rf / 100) × Rf + 0.7 × ((100 – Rf) / 100) × Rg’‘ + 0.15 × R9 + 0.15 × R12

Rg’‘ is calculated like this: 100 – (abs(100 – Rg) * (100 / Rg’)) – this tells us, how much the light source deviates from the black body line, if compared with other light sources having the same Rf.

So, for example, if an emitter with Rf=90, has an Rg of 93 (could be called very dull or greenish) or 107 (could be called very ill or rosy), has an Rg’‘ score of only 30, while light source spot on BBL would have Rg’‘ = 100.

The first two Rf based coefficients corrects for the cases, where e.g. Rf = 98 and Rg = 102 -> that is definitely not a bad light source, which would deserve Rg’‘ of 0.

Edit: Please ignore above anything I said related to Rg, as of maukka’s clarification.

Joshk
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staticx57 wrote:
Whats the advantage of this over something like CQS or TM-30?

Speed and simplicity would be the advantage. Can you imagine if I posted all 41 of the TM-30 (or CQS) diagrams and your job was to spot the best ones? Or sort them?

Joshk
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adam7027 wrote:
About CRI rendering: recently, I started to appreciate the newest CRI measuring method, which uses two values to present overall CRI. Rf (fidelity) is very similar in meaning to Ra (I won’t try to research for the differences now), and the other value is Rg (gamut), which tells, that how much the examined light source is greenish/yellowish (values under 100) or rosy (values above 100).

Rf measures as the same as Ra (range 0-100).
Rg measures from (100 minus Rg’) to (100 plus Rg’), where Rg’ = 100 – Rf

I would use a starting formula something like this:
0.4 × Rf + 0.3 × Rg’‘ + 0.15 × R9 + 0.15 × R12

Rg’‘ is calculated like this: 100 – (abs(100 – Rg) * (100 / Rg’)) – this tells us, how much the light source deviates from the black body line, if compared with other light sources having the same Rf.

So, for example, if an emitter with Rf=90, has an Rg of 93 (could be called very dull or greenish) or 107 (could be called very ill or rosy), has an Rg’‘ score of only 30, while light source spot on BBL would have Rg’‘ = 100.

That route crossed my mind, but where are you going to get all that data? It’s hard enough finding CRI data alone. Plus, Rg and Rf aren’t the same sensitivity as CRI, like you noticed, so fixing that is iffy and untrustworthy imho.

adam7027
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Joshk wrote:
adam7027 wrote:
…I updated my post, please copy that into your original quote of me

That route crossed my mind, but where are you going to get all that data? It’s hard enough finding CRI data alone. Plus, Rg and Rf aren’t the same sensitivity and output as CRI, like you noticed, so fixing that is iffy and untrustworthy imho.

Yes, I know, that this is hard to get, but all light sources, which was tested by maukka, have these data.

Joshk
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Like I say, it’s no replacement for reading a data dump if you can (and have it). But it sure is slick as an alternative grading method.

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adam7027 wrote:
Rg (gamut), which tells, that how much the examined light source is greenish/yellowish (values under 100) or rosy (values above 100).

TM-30 Rg describes how saturated colors seem on average. It’s not directly correlated with duv (magenta/green tint).

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Joshk wrote:
That route crossed my mind, but where are you going to get all that data? It’s hard enough finding CRI data alone. Plus, Rg and Rf aren’t the same sensitivity as CRI, like you noticed, so fixing that is iffy and untrustworthy imho.

Here’s a link to TM30-15 Excel calculator which you can use if you have SPD data from a spectrophotometer.

adam7027
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maukka wrote:
adam7027 wrote:
Rg (gamut), which tells, that how much the examined light source is greenish/yellowish (values under 100) or rosy (values above 100).

TM-30 Rg describes how saturated colors seem on average. It’s not directly correlated with duv (magenta/green tint).

Oh, good to know. Maybe more good examples would be needed here for my better understanding.

Still, basically, anytime I see an Rg above 100 in a measurement, the duv reading is negative and for Rg under 100, the duv reading is positive. Would be good to know, how indirect the correlation can be.

staticx57
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Joshk wrote:
staticx57 wrote:
Whats the advantage of this over something like CQS or TM-30?

Speed and simplicity would be the advantage. Can you imagine if I posted all 41 of the TM-30 (or CQS) diagrams and your job was to spot the best ones? Or sort them?

The inherit limitation as you’ve noted is the CRI Ra being limited the 8 pastel colors being tested. With something like TM-30 including a wider and deeper sample base the Rf means a lot more than CRI Ra.

maukka
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adam7027 wrote:
maukka wrote:
adam7027 wrote:
Rg (gamut), which tells, that how much the examined light source is greenish/yellowish (values under 100) or rosy (values above 100).

TM-30 Rg describes how saturated colors seem on average. It’s not directly correlated with duv (magenta/green tint).

Oh, good to know. Maybe more good examples would be needed here for my better understanding.

Still, basically, anytime I see an Rg above 100 in a measurement, the duv reading is negative and for Rg under 100, the duv reading is positive. Would be good to know, how indirect the correlation can be.

Here’s a couple examples:
Yuji BC duv -0.0024 Rg 96
Optisolis duv +0.0018 Rg 101

adam7027
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maukka wrote:
adam7027 wrote:
maukka wrote:
adam7027 wrote:
Rg (gamut), which tells, that how much the examined light source is greenish/yellowish (values under 100) or rosy (values above 100).

TM-30 Rg describes how saturated colors seem on average. It’s not directly correlated with duv (magenta/green tint).

Oh, good to know. Maybe more good examples would be needed here for my better understanding.

Still, basically, anytime I see an Rg above 100 in a measurement, the duv reading is negative and for Rg under 100, the duv reading is positive. Would be good to know, how indirect the correlation can be.

Here’s a couple examples:
Yuji BC duv -0.0024 Rg 96
Optisolis duv +0.0018 Rg 101

I see. Thank you.

Joshk
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maukka wrote:
Joshk wrote:
That route crossed my mind, but where are you going to get all that data? It’s hard enough finding CRI data alone. Plus, Rg and Rf aren’t the same sensitivity as CRI, like you noticed, so fixing that is iffy and untrustworthy imho.

Here’s a link to TM30-15 Excel calculator which you can use if you have SPD data from a spectrophotometer.

Thanks. I use LibreOffice Calc (instead of MS Excel), and it says it can not open those files because “the maximum number of columns per sheet was exceeded”.

But my meter gives me TM-30, Rf,Rg, SPD picture, all that with each reading, so I think I am covered.

The CRI_Grade system mostly fills my need to rank bulbs I have never tested against the ones I have.

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staticx57 wrote:
Joshk wrote:
staticx57 wrote:
Whats the advantage of this over something like CQS or TM-30?

Speed and simplicity would be the advantage. Can you imagine if I posted all 41 of the TM-30 (or CQS) diagrams and your job was to spot the best ones? Or sort them?

The inherit limitation as you’ve noted is the CRI Ra being limited the 8 pastel colors being tested. With something like TM-30 including a wider and deeper sample base the Rf means a lot more than CRI Ra.

Really though, R9 and R12 can be trusted to break away from the pack first, so even if Ra was including R10,11,13,14,15, it wouldn’t change much.

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