Light Bulb CRI_Grades

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.

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

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.

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

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

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.

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.

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

I see. Thank you.

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.

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.

Actually, it seems opposite to me. By including too many samples that average the same, you dilute the significance of R9 and R12, where the real differences are.

Having used a few bulbs that were below the BBL, I’m really not a fan for home/area lighting, if there’s any sunlight or other light sources it makes them look strange and artificial, and they make all other light sources look super green in comparison (even my calibrated computer monitor) which defeats the purpose IMO.

Low-CRI and -duv would be even worse, they look like fluorescents and I’d deal with swapping incandescent bulbs before going back to that, same reason I stick with high-CRI in my flashlights. The lack of much of the spectrum is immediately apparent to me personally.

Reminder that sunlight, fires, etc. (all the light sources we have evolved to be used to) are on or above the BBL. Rosy tint shouldn’t be taken as objectively desirable for all environments, that’s why Nichia for example offers specific tints and spectrum profiles for different types of retail, groceries, etc.

Sunlight is usually a lot higher CCT than any bulbs you can buy. What CCT are you using?
And I’m with you on not being impressed by rosy tints.

Also, on a super interesting note, I have the backlights from 2 PC monitors in that table! “DELL” is my PC, and “HP ENVY” is my wife’s. I opened Notepad to make a white screen, them measured with the meter against the screen.

You have to open the LM79 doc in the link I posted for you. It’s a complete lab assessment of the bulb

I’ve never heard you recommend the hyperikon bulbs either. Where did you buy the Sunlike bulb? link?

Hello Joshk, I saw you also started a topic regarding High CRI bulbs. Great initiative, you know how much I'm also looking forward to that!

May I suggest that instead of having two topics on BLF for a common subject, we unit our energy and efforts towards one community goal? As proposed and already started in the other topic, I'm pleased to discuss formula/scale, bulbs, or any other matter.

Ah, I see. That page has 16 links, I didn’t notice some were LM79. Thanks. It’s interesting. It seems to focus mainly on brightness in different rooms with different paint and flooring.

I bought the SunLike from

Sorry if you didn’t like the split, it wasn’t my intention. I didn’t want to spam the subscribers with my CRI_Grade proposal and discussion. Plus it could cause fatal confusion between your Qfactor and my CRI_Grade.
As you may know, BLF has no way to delete or merge threads.

Everyone, go ahead and keep posting interesting new light bulb finds on fneuf’s thread. This will remain a CRI_Grade thread.

Is the point to point out which lights have high R9?

TMI-30 includes additional output for situational measurement such as skin tones. Besides R9 not existing in TM-30 or CQS Wouldn’t it be better to base our BLF database on a more updated methodology?

I like the TM-30 diagrams (picture form), but the Rf and Rg it get summarized into are so in-sensitive I don’t find them very useful.

fneuf, can you please add a CRI_Grade column to your data so we can see how it performs?