80 vs 90 CRI... Convince me

Which is better

  • Total voters
    36
ChiefRunningPhist

ChiefRunningPhist

Well-Known Member
@hillbill
IR is just like light, it's either absorbed or reflected. If it's absorbed it will change form into some other type of energy.

LEDs put out a decent amount of IR, not much NIR though, but the heat is radiating off the heatsink at a certain WV/hz, just like the heat radiating off the surface of an HID. Ice radiates. In fact, everything emits IR.
 
Rocket Soul

Rocket Soul

Well-Known Member
Prawn Connery said:
OK, so I don't have the exact answer you require, but I've got a fairly close one. Those SPDs you posted are Nichias, which is what we're using for our High Light boards. The SPD below is a mix of CRI90 2700K V3-F1 (70% weighting) and Optisolis 2700K CRI97-98 (30% weighting). The RGB ratios are 11%, 37%, 47% with 5% FR.

View attachment 4379071

@Rocket Soul 's link on the previous page is interesting about CRI vs McCree weighting, but it's a bit old and also ignores the fact that measuring PAR from 400-700nm does not tell the full story. CRI90 has almost three times as much Far Red as CRI70 - all things (generally) being equal.

Also, CRI90 is catching up in terms of efficiency and when multiplied by Quantum Efficiency of Radiation, the numbers are not too bad. Those 2700K V3-F1s, for example, are 55.4% efficient at QER 4.96 for 2.75 umol/j. The CRI98 Optisolis do pull the overall board numbers down to 2.5 umol/j but they do boost the overall CRI to 95.
Click to expand...
Prawn Connery said:
OK, so I don't have the exact answer you require, but I've got a fairly close one. Those SPDs you posted are Nichias, which is what we're using for our High Light boards. The SPD below is a mix of CRI90 2700K V3-F1 (70% weighting) and Optisolis 2700K CRI97-98 (30% weighting). The RGB ratios are 11%, 37%, 47% with 5% FR.

View attachment 4379071

@Rocket Soul 's link on the previous page is interesting about CRI vs McCree weighting, but it's a bit old and also ignores the fact that measuring PAR from 400-700nm does not tell the full story. CRI90 has almost three times as much Far Red as CRI70 - all things (generally) being equal.

Also, CRI90 is catching up in terms of efficiency and when multiplied by Quantum Efficiency of Radiation, the numbers are not too bad. Those 2700K V3-F1s, for example, are 55.4% efficient at QER 4.96 for 2.75 umol/j. The CRI98 Optisolis do pull the overall board numbers down to 2.5 umol/j but they do boost the overall CRI to 95.
Click to expand...
I linked that thread cause (iirc) later on he did a 4 way side by side, 3000k 90 cri won over 2700k 90 cri and 3000k 80/70cri. Very nice thread btw. Back then there was quite a few side by sides investigating 90 cri but there was allways some kinda confounding thing happening. Rahz's grow: involuntary extra vegg which meant extra cannopy size for 90 cri.
https://www.rollitup.org/t/quantum-boards-3000k-80-cri-vs-3000k-90-cri.941486/
Captain morgans comparison, matching ppfd between 80 and 90 cri: 90 cri got some light burn and i cant remember exactly how it turned out.
https://www.rollitup.org/t/dhp-presents-citizen-cob-1812-3500k-80cri-vs-1812-3500k-90-cri.932990/
The dawgs comparison: very equal results, but the 90 cri plant was defoliated slightly which shocked it and made it stop growing.

@ChiefRunningPhist
Ive been intrigued by what you say about green, some of it i read aswell. But then other reading seems to indicate green light maybec the stomata which cant really be good, especially with leds. But maybe its a discussion for another time and place :)

@OP
If my memory serves me i saw somewhere here on riu yet another comparison where some terpenes only turned up in the 90 cri side. Hard to remember who did it, i thought it was nevergoodenough but i cant find the thread in his history.

Ive seen flowering with 2700k 90 cri myself and it was very obvious that it went better. Faster bud set, bigger more sticky buds, slightly better yields yadayada
4000k 90 cri was visually similar to 3000k 80 cri.
Another point Rahz made about 90cris: about 2 inches more of stretch per week of vegg.
Transition/stretch: transition was faster in 90 cri so about half the stretch compared to 80 cri.
Ive also seen people say faster finishing times.

I dont have all the data but i have seen enough to form an opinion, both irl and online. 90 cri flowers better, and most likely veg aswell. But you could almost just aswell add some red and far red for same result.
Ymmv.
 
Rocket Soul

Rocket Soul

Well-Known Member
ChiefRunningPhist said:
@hillbill
IR is just like light, it's either absorbed or reflected. If it's absorbed it will change form into some other type of energy.

LEDs put out a decent amount of IR, not much NIR though, but the heat is radiating off the heatsink at a certain WV/hz, just like the heat radiating off the surface of an HID. Ice radiates. In fact, everything emits IR.
Click to expand...
I dont think white leds put out any IR. It gets rid of heat by convection. The reason you can feel heat under leds is that regular light also heats the plant.
 
ChiefRunningPhist

ChiefRunningPhist

Well-Known Member
Rocket Soul said:
I dont think white leds put out any IR. It gets rid of heat by convection. The reason you can feel heat under leds is that regular light also heats the plant.
Click to expand...
The chip isn't 100% effecient, it's maybe only ~65% effecient, that's why you need heatsinks. Not for the 65% but for the 35%. Anything past NIR is IR.

The driver reduces wall watts maybe 7%, and the chips further eat into this at about 55% - 67% depending on how you're set up.
 
Rocket Soul

Rocket Soul

Well-Known Member
Yes but heat is not the same as IR. IR causes heat, and enough heat will cause IR. But in order to cause IR it needs a very high temprature, much higher than the 55ish C people usually have in their heatsinks.
 
ChiefRunningPhist

ChiefRunningPhist

Well-Known Member
Rocket Soul said:
Yes but heat is not the same as IR. IR causes heat, and enough heat will cause IR. But in order to cause IR it needs a very high temprature, much higher than the 55ish C people usually have in their heatsinks.
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They the same thing. It requires a certain amount of heat to create visible, like for black body irradiance, but literally anything above 0° K emits IR.

EDIT:
This says 5°K..
Screenshot_2019-08-14-12-35-23~2.png
If the waste energy isn't being transformed into kinetic, or being convected/conducted, then its being emitted as IR. The heatsink, PCB, and air, doesn't effectively take all waste energy.

To say they throw tons of IR is an overstatement and I'll pull back my initial sentiment a bit, but they do emit some IR, a lot more than I think we typically imagine. Idk what WVs or how beneficial it is, but it is there. If you removed the air from the room you'd still be able to feel the heat radiating to your hand from a distance, the air helps to dissipate some of it, and so does the heatsink but they eventually heat up and emit then as well.
 
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hillbill

hillbill

Well-Known Member
ZHChris said:
80cri,save your money，and more lumens
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I have both and not a lot of $ saved there but the 90cri is “warmer” looking and it may have shaved a couple days off flower along with 10/14 schedule.

Really though the difference between most 3000k to 3500k COBs is nothing compared to the difference in spectrum from HPS and any of these COBs. Efficiencies seem within a few percent also. Most of my lights are far from the latest and greatest these days but WAY better than HID.
 
ChiefRunningPhist

ChiefRunningPhist

Well-Known Member
Rocket Soul said:
I linked that thread cause (iirc) later on he did a 4 way side by side, 3000k 90 cri won over 2700k 90 cri and 3000k 80/70cri. Very nice thread btw. Back then there was quite a few side by sides investigating 90 cri but there was allways some kinda confounding thing happening. Rahz's grow: involuntary extra vegg which meant extra cannopy size for 90 cri.
https://www.rollitup.org/t/quantum-boards-3000k-80-cri-vs-3000k-90-cri.941486/
Captain morgans comparison, matching ppfd between 80 and 90 cri: 90 cri got some light burn and i cant remember exactly how it turned out.
https://www.rollitup.org/t/dhp-presents-citizen-cob-1812-3500k-80cri-vs-1812-3500k-90-cri.932990/
The dawgs comparison: very equal results, but the 90 cri plant was defoliated slightly which shocked it and made it stop growing.

@ChiefRunningPhist
Ive been intrigued by what you say about green, some of it i read aswell. But then other reading seems to indicate green light maybec the stomata which cant really be good, especially with leds. But maybe its a discussion for another time and place :)

@OP
If my memory serves me i saw somewhere here on riu yet another comparison where some terpenes only turned up in the 90 cri side. Hard to remember who did it, i thought it was nevergoodenough but i cant find the thread in his history.

Ive seen flowering with 2700k 90 cri myself and it was very obvious that it went better. Faster bud set, bigger more sticky buds, slightly better yields yadayada
4000k 90 cri was visually similar to 3000k 80 cri.
Another point Rahz made about 90cris: about 2 inches more of stretch per week of vegg.
Transition/stretch: transition was faster in 90 cri so about half the stretch compared to 80 cri.
Ive also seen people say faster finishing times.

I dont have all the data but i have seen enough to form an opinion, both irl and online. 90 cri flowers better, and most likely veg aswell. But you could almost just aswell add some red and far red for same result.
Ymmv.
Click to expand...
I'm down, pm or new thread? idc. And I agree, I'm aware of the paper showing excess green can lead to less than desirable outcomes (can't remember what chemical was reduced), but I'd have to look at it again or you'd have to refresh my memory.
 
Rocket Soul

Rocket Soul

Well-Known Member
ChiefRunningPhist said:
I'm down, pm or new thread? idc. And I agree, I'm aware of the paper showing excess green can lead to less than desirable outcomes (can't remember what chemical was reduced), but I'd have to look at it again or you'd have to refresh my memory.
Click to expand...
:)

Yes this is getting away from the CRI subject. Maybe IR and green is for another time and the other place... Gotta go, my wife wants me on holiday and not riu
 
Prawn Connery

Prawn Connery

Well-Known Member
Rocket Soul said:
I linked that thread cause (iirc) later on he did a 4 way side by side, 3000k 90 cri won over 2700k 90 cri and 3000k 80/70cri. Very nice thread btw. Back then there was quite a few side by sides investigating 90 cri but there was allways some kinda confounding thing happening. Rahz's grow: involuntary extra vegg which meant extra cannopy size for 90 cri.
https://www.rollitup.org/t/quantum-boards-3000k-80-cri-vs-3000k-90-cri.941486/
Captain morgans comparison, matching ppfd between 80 and 90 cri: 90 cri got some light burn and i cant remember exactly how it turned out.
https://www.rollitup.org/t/dhp-presents-citizen-cob-1812-3500k-80cri-vs-1812-3500k-90-cri.932990/
The dawgs comparison: very equal results, but the 90 cri plant was defoliated slightly which shocked it and made it stop growing.
Click to expand...
My turn for an apology. I'm slowly making my way through that thread and the points I raised were discussed further in. I was commenting on the initial findings - I shouldn't have been so hasty (or stoned!). We did our own tests on CRI80 3000K vs a mix of CRi80/90 3000K (QB324 boards) and found the extra red finished flowering a few days earlier on an 8-week strain with no reduction in yield: https://www.rollitup.org/t/qb324-grow.972640/
 
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