PSUAGRO.
Well-Known Member
guod is just feigning/playing with his ignorance, little devil knows the #s better than anyone here
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3500k vs 4000k vs 5000k ?
- Thread starter Trippyness
- Start date
JorgeGonzales
Well-Known Member
I was agreeing with him!
monkeychief
Well-Known Member
.
You can choose the intensity you want to run within reasonable limits, with a hps, leds with a suboptimal spectrum, or leds with a more ideal spectrum. If maximum intensity is key (it's a very imporant factor but not the only one) the more reason to use an optimal spectrum. With hps you will burn the plants before you reach the max intensity, not just from the IR, while with an optimal spectrum you can push the range where it actually makes sense without pushing range where it doesn't.
Max intensity per cob does not determine the max intensity on the plant. Max intensity, high efficiency, and a better spectrum are not mutually exclusive.
@Sativied. Si amigo. Intensity is the key and will make even crappy spectrum produce decent to good results. Spectrum determines it's efficacy.
You can choose the intensity you want to run within reasonable limits, with a hps, leds with a suboptimal spectrum, or leds with a more ideal spectrum. If maximum intensity is key (it's a very imporant factor but not the only one) the more reason to use an optimal spectrum. With hps you will burn the plants before you reach the max intensity, not just from the IR, while with an optimal spectrum you can push the range where it actually makes sense without pushing range where it doesn't.
Max intensity per cob does not determine the max intensity on the plant. Max intensity, high efficiency, and a better spectrum are not mutually exclusive.
@Sativied. Si amigo. Intensity is the key and will make even crappy spectrum produce decent to good results. Spectrum determines it's efficacy.
guod
Well-Known Member
another tidbit...
posted about 3 years ago...
https://www.rollitup.org/t/cree-cxa-analysis.743645/page-2#post-9766199
seems you have some problems in understanding relative and absolute graphs
Atulip
Well-Known Member
Cxb3590 90cri is only 1 bin lower than 80cri. I'm not sure how Vero10 spectrum compares but I think 3590 90cri is more than Vero10 97cri?
alesh
Well-Known Member
I was under an impression that we're not talking about an obsolete version of Vero10.
The top bin CXB3590 90CRI 3000K (BD) has about 23% higher photon output in the 640-660nm region compared to the top bin 80CRI 3000K (CB). That's a fact.
Used data from PCT at 25° C.
alesh
Well-Known Member
1) The graphs are 3000K.
2) The graph you posted certainly doesn't reflect data from the sixth gen of Vero10 as does the table you posted.
3) The graph you posted is probably Vero Decor series and not the one in the table.
putting efficiency aside...
In my own grows I can conclusively say that a warm white phosphor spectrum outperforms any primarily red/blue spectrum out there. Even the illumitex F3 spectrum sucks in comparison. Over the past few years I have been working with T5HOs, specialized aquarium tubes, disposable Chinese leds, small diode leds and cobs with various wavelength mixes and testing all sorts of different combinations.
A 90 CRI warm white phosphor grows better than a 70 or 80 cri spectrum, but generally the loss in photons isn't worth it.
My testing work going forward is on how to enhance the typical white phosphor spectrum with the least amount of supplementation for the best spectrum.
As far as genetic response to different spectrums.... while genetic differences to different spectrums are apparent, for the most part most cannabis subspecies, varieties and phenos, respond to the different spectrums in the same way within their genetic capability.
e.g. A short squat wide leaf indica will stretch more under a spectrum heavy in deep red/ far red. But so will a thin leaved tall strectchy pure sativa.
and just what is the efficiency of xpg3 ?
thanks for the graph. now I understand why the 90 cri is more efficient than their older 90 cri spectrum. add more blue, subtract a bit around yellow/orange and add a bit of deep red.
My initial reaction is the 80 cri spectrum is likely to outperform this new 90 cri spectrum, because of the drop in the 590-630 nm range. The 80 cri supplemented with a few deep reds will probably do even better. I guess you could supplement this new 90 cri mix with some yellow light and achieve the same thing .... but whats the point ?
puffenuff
Well-Known Member
Key words:
"In my own grows" -- cool that only applies to you and the red/blue lights you've used
"outperforms any primarily red/blue spectrum out there" -- but you haven't tested them all...
I posted a pic in the LED Users Unite thread last week that shows two nugs, one grown under white and the other under red/blue. There's literally no way anyone can say one spectrum outperformed the other. All I'm saying is both work just fine.
yes absolutely I haven't tested all combos, but photons are photons and I have been through a whole bunch of different combinations.
a pic showing flowers grown under two different spectrums only tells a small part of the story. says nothing about yield, penetration into the canopy, or plant structure. I don't disagree that a decent blurple light can grow great flowers, BUT i'm way beyond growing individual prize colas. Try cranking up the overall intensity over 1200 ppfd of a blue/red spectrum and see what happens.
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puffenuff
Well-Known Member
The rest of the story is that yields were similar, no larf down low, and the plants were both perfectly normal on both sides.
BobCajun
Well-Known Member
From my research, growth increases with up to 50% blue light, then it starts reducing. I don't think any type of white LED puts out more than 50% but the higher CCT ones should be the closest to it.
Here's a pic someone else posted showing the amounts in some CCTs. Even 5000k is nowhere near 50%. Green also reduces growth at over 50%, and most CCTs are very close to that. Green is good for deep penetration though, so at that level it may be alright. Interestingly, the 5000k have about equal amounts of blue and red, which may be a good thing. Just that both are only about half as much as the green.
I've mentioned about green reducing growth when over 50% before, with a few vehement detractors. However, the reduction is not dramatic. You can grow plants under pure green light and they'll only be slightly lower in dry weight than those under red, blue or combination thereof. So it's not a case of green light being horrible, just that it would be your last choice if you had to choose a single color.
Here's a pic someone else posted showing the amounts in some CCTs. Even 5000k is nowhere near 50%. Green also reduces growth at over 50%, and most CCTs are very close to that. Green is good for deep penetration though, so at that level it may be alright. Interestingly, the 5000k have about equal amounts of blue and red, which may be a good thing. Just that both are only about half as much as the green.
I've mentioned about green reducing growth when over 50% before, with a few vehement detractors. However, the reduction is not dramatic. You can grow plants under pure green light and they'll only be slightly lower in dry weight than those under red, blue or combination thereof. So it's not a case of green light being horrible, just that it would be your last choice if you had to choose a single color.
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JorgeGonzales
Well-Known Member
This is kinda rad. Another way of looking at it is a binning anomaly. Even though you are moving down a bin, those bins are based on lumens, where the 90CRI still pulls ahead thanks to Planck and moving some greens out into red/far red, skewing lumens down and umols/J up.
So the 90CRI top bin has higher photon efficiency than the 80CRI, and a nice spectrum. @Sativied will be very happy, although perhaps be confused that a blue led can be more efficient skewed red with phosphur.
Once again, Cree's binning is a very nice thing. That isn't going to happen for unbinned manufacturers I don't think. Is there a markup for 90CRI?
I ran some relative percentage numbers last night, some more shitty spreadsheet skills on display. Pie charts are kind of pointless in retrospect:
80CRI
90CRI
Greengenes707
Well-Known Member
Where is that research? Links and citing please?
That doesn't line up with anything published in the last 40 years. Photoinhibition starts way earlier...some think under 20%...most show ~25%.
JorgeGonzales
Well-Known Member
Not to muddy the waters, but testing photoinhibition with single nm leds might not be particularly applicable to broad spectrum lighting. Having said that, the sun is about 25% blue as a relative percentage of PAR. Interestingly, green is about 36%, much to the horror of @BobCajun I suspect
I'm curious about the optimal r:fr ratios. That's the biggest difference in the 90CRI.