High CRI 90+ vs. Efficacy

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churchhaze

Well-Known Member
Sativied said:
They told me, and anyone but the cooler white cob fans, they would prefer the for them more efficient light from 2700-3000k 90cri over
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They told you? So you have tried 3000k 80cri, 3500k 80cri and the 90cri versions and you noticed a big difference? Can you tell us about your experience? Have you tried the cool white 90cri like you're bashing @REALSTYLES for trying? I'm pretty sure he just wants to see what happens. Plants can not tell you about what they don't see. He is making REAL observations and letting us see his results. I don't think anyone really expects it to do better than warm white.

First I made 3000k 80cri panels, then I made 3500k 80cri panels, then made my cxb panels 3000k 80cri again because I thought warm white did a better job. In retrospect, I don't notice much of a difference between how my 3000k 80cri plants and 3500k 80cri plants look. The 3000k might be doing better, but I don't notice a difference. You speak with so much conviction, but you have nothing to back it up other than a bunch of absorbance charts. (the same charts that convinced people to grow with red traffic signals in 2005).
 
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churchhaze

Well-Known Member
Sativied said:
They told me, and anyone but the cooler white cob fans, they would prefer the for them more efficient light from 2700-3000k 90cri over the commonly used veg lights.
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I guess what I really mean to say.... please quit this stupid fight about 3000k 80cri vs 3000k 90cri. It's too much blue that causes photoinhibition. You keep saying that yellow is wasted light but that's clearly not the case or HPS would be useless.

You were a lot more useful to noobs back when you recommended HPS. Such a nice spectrum.. So much amber... so little blue...

You know which group on here uses too much blue and yields fluffy airy buds, but you don't want to pick a fight with those guys. (inconvenient?)

Meanwhile, noobs are upgrading their HPS to T5 because of what experts recommend.

The best advice to most noobs around here is to buy an HPS lamp and to avoid all T5 hype. The LED argument is moot point unless people with 3000 90cri start seeing BIG results when compared to 3000k 80cri. Until then, why should anyone care which one they have?
 
ttystikk

ttystikk

Well-Known Member
churchhaze said:
I guess what I really mean to say.... please quit this stupid fight about 3000k 80cri vs 3000k 90cri. It's too much blue that causes photoinhibition. You keep saying that yellow is wasted light but that's clearly not the case or HPS would be useless.

You were a lot more useful to noobs back when you recommended HPS. Such a nice spectrum.. So much amber... so little blue...

You know which group on here uses too much blue and yields fluffy airy buds, but you don't want to pick a fight with those guys. (inconvenient?)

Meanwhile, noobs are upgrading their HPS to T5 because of what experts recommend.

The best advice to most noobs around here is to buy an HPS lamp and to avoid all T5 hype. The LED argument is moot point unless people with 3000 90cri start seeing BIG results when compared to 3000k 80cri. Until then, why should anyone care which one they have?
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Nonononono! You've got it all wrong! Only 3500K is any good, all the rest is total shit! :P
 
Rahz

Rahz

Well-Known Member
My thoughts on the subject. High CRI in and of itself is only desirable because the red peaks at 630. Looking at the relative charts can make it seem like high CRI is a much better deal, but it's not an entirely accurate picture. Take this absolute chart comparing the CXA spectrum. I don't remember who went to the effort to produce it (?) my apologies for that.

spectral flux.png

You can see the 3000K 80CRI is providing more 630nm light and is equaling the high CRI counterpart at 650nm. The high CRI does win at 680 but not by enough in my mind to justify the switch.
 
cdgmoney250

cdgmoney250

Well-Known Member
Judging by that picture, the high CRI still seems to be the best choice of spectrum. Now that I have some real world experience with these chips, delivering enough photons to the canopy with COB's is of no concern.
It's actually exceptionally easy to do.
Might as well pick the best color recipe to do it. Matching irradiance with different Kelvin temps is not difficult to do.
 
ttystikk

ttystikk

Well-Known Member
My 3500K CXB3590 chips work amazingly well everywhere I use them. Best veg ever, period. And bloom lighting that's setting personal best yield and quality numbers even while things are far from dialed in.

The plants certainly want for nothing more than this. If improvements can be made by tinkering with spectrum I'm all ears, but I'm still skeptical that the incremental gains are worth the effort and expense incurred.

So how does one test for and quantify such incremental gains? For example, it isn't hard to see the quality and performance difference between HPS and CDM/CMH. Likewise, the difference between the above and COB LED is if anything even more obvious and I'm in the process of quantifying it by weight. Would one expect a similar boost with the higher CRI lighting? My own experience suggests not; 860W CDM Allstart lamps are 93 CRI. Nothing magical happens.

I'm only two cycles into blooming with my COB LED and I wouldn't part with them for anything else on the market, full stop.
 
JorgeGonzales

JorgeGonzales

Well-Known Member
Rahz said:
My thoughts on the subject. High CRI in and of itself is only desirable because the red peaks at 630. Looking at the relative charts can make it seem like high CRI is a much better deal, but it's not an entirely accurate picture. Take this absolute chart comparing the CXA spectrum. I don't remember who went to the effort to produce it (?) my apologies for that.

View attachment 3735875

You can see the 3000K 80CRI is providing more 630nm light and is equaling the high CRI counterpart at 650nm. The high CRI does win at 680 but not by enough in my mind to justify the switch.
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I think that's a pretty ancient chart. @alesh said awhile back that the 90CRI CXB stuff too close vs the 80 CRI now, in photons if not energy.

Recent tests with the Citizen stuff show the 90 CRI stuff doing pretty well against the 80 CRI, holding up to theoretical umol/J predictions using the same methods as alesh. Especially impressive since a few percent far red isn't being measured above 700nm.

Most recently, Malocan's PPFD measurements have the 2700K 90CRI 1825 ahead of the CXB3590 3500K CD in straight up, real world tests. Kind of cool.
 
ttystikk

ttystikk

Well-Known Member
JorgeGonzales said:
I think that's a pretty ancient chart. @alesh said awhile back that the 90CRI CXB stuff too close vs the 80 CRI now, in photons if not energy.

Recent tests with the Citizen stuff show the 90 CRI stuff doing pretty well against the 80 CRI, holding up to theoretical umol/J predictions using the same methods as alesh. Especially impressive since a few percent far red isn't being measured above 700nm.

Most recently, Malocan's PPFD measurements have the 2700K 90CRI 1825 ahead of the CXB3590 3500K CD in straight up, real world tests. Kind of cool.
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Yeah, I want to look into those myself.

I'm a fan of holding the color temp in the 3500-4000K range, mainly because it mimics daylight best.
 
alesh

alesh

Well-Known Member
JorgeGonzales said:
I think that's a pretty ancient chart. @alesh said awhile back that the 90CRI CXB stuff too close vs the 80 CRI now, in photons if not energy.

Recent tests with the Citizen stuff show the 90 CRI stuff doing pretty well against the 80 CRI, holding up to theoretical umol/J predictions using the same methods as alesh. Especially impressive since a few percent far red isn't being measured above 700nm.

Most recently, Malocan's PPFD measurements have the 2700K 90CRI 1825 ahead of the CXB3590 3500K CD in straight up, real world tests. Kind of cool.
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It is ancient.
Actually, in terms of photon output, CXB3590: 3000K BD 90CRI > 3500K CD 80CRI
 
Rahz

Rahz

Well-Known Member
It is an old chart, but proves the point that high CRI is not directly related to output or a specific color ratio.

I like the Citizen profiles, plenty of blue at 3000K, also notice the new Vero has over 50% relative power at 450 now which makes 3000K 80CRI more appealing than it has been.
 
C

churchhaze

Well-Known Member
Can someone actually show us in practice 3000k 90cri beating 3000k 80cri conclusively? (rather than just talking about the theory of how plants like red)
 
C

churchhaze

Well-Known Member
Also, the fact that you can use a light source with only 660nm, high quantum flux can lack power. (all the smaller wavelengths). The only reason ppf seems like a better measurement than W is because plants don't need much blue. (so most of the time it ends up being right) Neither ppf nor W of PAR alone tells you the whole story. The idea that you can just keep making your spectrum redder to get higher umol/J is absurd. It only works if you don't already have enough red. If you do, all of the sudden PAR W seems like the more important number. Some of your photons need more energy than others!

The only reason umol/s seems more important than W is because plants don't need much blue. If plants wanted a spectrum higher in blue than warm wavelengths, people would conclude that PAR efficiency is a more accurate measure than quantum efficacy. Reality is that neither tell you the whole story.

When spectrum is held constant, PAR W and umol/s basically mean the same thing. (neither is more accurate nor correct)

Edit: My point is that I just can't see how PAR W is insufficient and that somehow umol/s is a more precise number. It seems like you're just playing with numbers to find the best ways to market the products.
 
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alesh

alesh

Well-Known Member
Rahz said:
It is an old chart, but proves the point that high CRI is not directly related to output or a specific color ratio.

I like the Citizen profiles, plenty of blue at 3000K, also notice the new Vero has over 50% relative power at 450 now which makes 3000K 80CRI more appealing than it has been.
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Anyway, CXB3590 3000K 80CRI vs 90CRI, minimal values, temp set to 25°C in PCT.
chart01.jpg
 
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