Nichia 219C

[jon_slider]

What good is 83 CRI? I like Nichias in the 90's

its a tradeoff.. people into lumens, think Cree rules. So to increase sales to that market segment, Nichia is increasing Lumens to satisfy market demand. Yes, when Lumens go up CRI goes down, its a tradeoff.

and fwiw, I have an L3 Illumination L08 with N219A rated 4500K and 92 CRI, it actually tested at 4400K and 88 CRI. The High Mode is rated at 90 Lumens

by contrast my Olight i3s with XP-G2 tested at 6000K and 71 CRI. The high mode is rated at 85 Lumens

so imo, Nichia is Already competitive in brightness with Cree, and Nichia has significantly more CRI.

But if you watch the trend, you will see that each new version of Nichia N219 is brighter (and cooler with lower CRI) than the last. Because the market segment that prioritizes brightness, does not know about, or care about, prioritizing CRI.

I had a light with N219b, I sold it as for my needs it was too blue. So, no chance I will be interested in a N219c, which imo is moving away from CRI, and towards bluer and brighter LEDs, a domain that Cree has dominated, and that Nichia wants a share of.

 

[markr6]

What good is 83 CRI? I like Nichias in the 90's

If the brightness is close enough to the other LEDs which are many times 65-75CRI, the 83 would be a nice bonus. But I agree...I want the 90+!

 

[more_vampires]

90 CRI is okay, but I want 100+ cri. That way I see more colors than are there! :)

 

[Pöbel]

Overriding leds for maximum lumens is a tiny niche need. If we want this to be an attractive choice for manufacturers, we need to concentrate on the numbers that are within the specifications.

From the manufacturer pages above:

• XP-G2 (S2?): Maximum Light Output 515 lm @ 4.7 W (85°C) (110lm/W)
• 219C: 1800 mAh * 3,23V = 586lm @ 5,8 W (100lm/W)

From the test results:

• XP-G2 S4: 1,4A & 3,39V => 581 lm @ 4,7W (122lm/W)
• 219C: 1,8A & 3,12V => 622 lm @ 5,6W (111lm/W)

Not bad.. For a slightly warmer led with better cri..

As a side note, the test voltages for XP-G2 are quite a bit higher than the datasheet values. The datasheet curve suggests something like 3,14 V at 1,5A. The test sample is 3,39V at 1,4A and 3,45V at 1,6A. Also, the datasheet at Cree homepage is half a month old and defines S2 as the highest bin. :thinking:

edit: Binning and labeling sheet (published in April) has S3 as the highest bin.

although some manufacturers like ThruNite and armytek do overdrive some of their LEDs you are right if its about production lights.

for us enthusiasts modifying lights that picture changes

 

[recDNA]

It is nonsense to say more output means cooler and lower cri. There is a high cri xpg2 at 3000k which has more output than 219b. Some 219b are rated in 90's
I have a 4000 k xml2 rated at 85 cri that beats 219c in cri and output.

 

[Pöbel]

within one product cool is more efficient than warm as the light has to pass less phosphor

also this thread is about 219c, not b

 

[Anders Hoveland]

It is nonsense to say more output means cooler and lower CRI.

Not always, but there is a general trend for that to be the case. I would agree though that the brand and model of emitter can make more of a difference.

 

[Camo5]

Did some research and found this article fascinating. http://www.photonics.com/Article.aspx?AID=28677
According to this, that 90+ cri 4500k bin led nichia is working on is basically exactly where it needs to be for maximum efficacy! :grin2::popcorn:
Granted that's for a 4 color laser diode setup...

"The maximum CRI is 91 for a CCT of 4468 K with a theoretical efficacy of 358 lm/W."

 

[Esko]

Did some research and found this article fascinating. http://www.photonics.com/Article.aspx?AID=28677
According to this, that 90+ cri 4500k bin led nichia is working on is basically exactly where it needs to be for maximum efficacy! :grin2::popcorn:
Granted that's for a 4 color laser diode setup...

"The maximum CRI is 91 for a CCT of 4468 K with a theoretical efficacy of 358 lm/W."

You are mixing things up. Those results could be applied to RGB/RGBA type leds. Phosphor conversion leds are different animals.

OT: Regarding the link, there is a chart that presents wavelength values for producing maximum cri 'white' light by monochromatic systems. As a hobbyist, I find it rather surprising that by mixing 476nm (light blue) and 532nm (green), you can get warm "white" light at 2940K. Then, pretty much by adding yellow and red (mixing 464nm (blue), 526nm (green), 583nm (yellow) and 634nm (orange)), you can get neutral white at 4468K. Nothing surprising in the latter one, however, if I had had to guess, I would have thought that the first one should be at least some 1000K higher.

edit: Applied to RGB/RGBA leds except that 1. in real life you have less choices for wavelengths and 2. you could get better cri because leds are not as monochromatic as lasers.

 

[Anders Hoveland]

I find it rather surprising that by mixing 476nm (light blue) and 532nm (green), you can get warm "white" light at 2940K.

Good luck with that. By looking at the CIE color graph it is easy to see this simply is not true. You can however make warm white light by mixing 495nm greenish-cyan with red light.
(it can get a little confusing because generally cyan LEDs are much more green-colored than their rated peak wavelength, the spectral emission from LEDs is not as narrow as atomic spectral lines)

 

[Xak]

So which will be warmer? 219b or 219c? Thinking of getting a custom triple nichia, should I wait until the 219c is out?

 

[SemiMan]

So which will be warmer? 219b or 219c? Thinking of getting a custom triple nichia, should I wait until the 219c is out?

CCT "warmer", will make absolutely no difference. It will come down to the individual LED you buy. From a heat temperature, they 219C if you have a good bin.

 

[Xak]

Any rumors as to when they might be available?

 

[DIWdiver]

Not always, but there is a general trend for that to be the case. I would agree though that the brand and model of emitter can make more of a difference.

+1

I think it's true (and SemiMan will probably correct me if I'm wrong) that once you make the die and you are choosing phosphors, these are pretty hard and fast rules. If you choose phosphors for a lower CCT, you will have lower lumen output than if you choose ones for higher CCT. Likewise, choosing phosphors for higher CRI will give lower output than ones for lower CRI.

This may be partly due to efficiency of the phosphors, but it is definitely partly (or completely) due to the sensitivity of the human eye. At longer wavelengths (warmer CCT, red, orange, yellow) it takes more optical power to product a lumen of visible light. If the radiometric efficiency is constant, the luminous efficacy is lower for warmer colors. This is a biological phenomenon, not subject to improvement through LED technology.

The same thing occurs at the short-wavelength end of the visible spectrum. Extremely high CCT emitters would suffer the same problem. But there's little or no discussion of this because (almost) nobody cares.

 

[SemiMan]

Also need to mention Stokes losses. Phosphors, at least those available today, all have a quantum efficiency <= 1. One photon in, one photon out. However the energy in those photons is not the same. The shorter the wavelength the more energy. The blue/violet pump photon had more energy than the green or red released photons even if the phosphor has 100% quantum efficiency.

 

[djozz]

DBcustom from the blf forum spoke to a Nichia representative recently, and got the information that (despite that it is listed on the Nichia website as being under developement) Nichia is not working on the 90+ CRI version of the Nichia 219C. :-(

 

[jon_slider]

… If you choose phosphors for a lower CCT, you will have lower lumen output than if you choose ones for higher CCT. Likewise, choosing phosphors for higher CRI will give lower output than ones for lower CRI.

This may be partly due to efficiency of the phosphors, but it is definitely partly (or completely) due to the sensitivity of the human eye. At longer wavelengths (warmer CCT, red, orange, yellow) it takes more optical power to product a lumen of visible light. If the radiometric efficiency is constant, the luminous efficacy is lower for warmer colors. This is a biological phenomenon, not subject to improvement through LED technology.

agree, as CRI goes up Lumens go down…

specific example based on Nichia chart below, increasing CRI by 13% reduces intensity by 12%:

80CRI and 83 intensity, compare to
90CRI (+13% from 80) with 73 intensity (-12% from 83)

http://www.nichia.co.jp/en/product/led_search.html?op=cond=whatsnew='19C'

 

[lyyyghtey]

DBcustom from the blf forum spoke to a Nichia representative recently, and got the information that (despite that it is listed on the Nichia website as being under developement) Nichia is not working on the 90+ CRI version of the Nichia 219C. :-(

Well that's not good news at all. :( But doesn't Mtn Electronics seem to have some of them?

 

[markr6]

DBcustom from the blf forum spoke to a Nichia representative recently, and got the information that (despite that it is listed on the Nichia website as being under developement) Nichia is not working on the 90+ CRI version of the Nichia 219C. :-(

Ah, well I didn't want to say "I told you so", but...

 

[dc38]

Well that's not good news at all. :( But doesn't Mtn Electronics seem to have some of them?

For some reason...my https to mtnelectronics is red...meaning the lack of one?