DIY LED grow lights experiences

With Leds (only with leds ) high CRI means/translates more red in a phosphor convertion white led ..


A (fictional ) High CRI HPS ,would have had more blue (as it lacks blue,to reproduce/render all hues correct ... )

So CRI ,is also a RELATIVE (to certain color standards ) " unit /index ".....

With leds (and growing ) for efficiency ,only the Flux (mW ) / Electrical Power (Watts ) ,radiometric efficiency is important ....

Having the photometric efficiency ( lumens/ Electrical Power ) given only ,
one needs: the led's relative spectral graph ,
the human vision - CIE standard- sensitivity graph ( the photopic one )
and lots of math calculations ,so to estimate the actual radiometric flux ....(and radiometric efficiency...)


Lumen/Watt ,that figure ,by itself ,doesn't mean anything ..
Nothing at all ..

Totally useless for use in horticultural illumination ...

GS - i was puzzled when you were bashing the oslon WW for efficiency before

If cree give you the XTE's radiometric efficiency, or you sit down and do the math, do share - Im not planning on using XTE again soon, but i'd be curious what the stats are like on my existing XTE panel.

Snoot....dont be so sure about it

The concept of using a color mix to achieve high CRI and high efficacy in warm-white SSL products came originally from Cree in the True White products. More recently, Osram Opto Semiconductors has supported the concept with its Brilliant Mix technology.

"In any case, the idea is to use red or amber LEDs to add spectral power in the visible red wavelengths in an efficient manner. Phosphors that can deliver such wavelengths are generally inefficient because they also generate energy that falls outside the human-visible spectrum, thereby wasting energy"

"That's been my observation as well. The CRI is higher because of the boost in Cyan output. The standard warm emitter always looked very pink because of it's high Red output. The higher Cyan in the HCRI counteracts this and the colour is much more balanced, in my eyes at least"

...according to this, higher CRI is accomplished to blend in more than just the red?

And I am afraid that radiometric figures if not available don't mean you just trash the more lumens figures... At least I ain't going to do it

The point is, that all the lumens are, is the radiometric output biased towards the human eye!
As guod points out - with a known lm/W, and known spectral distribution, you can convert "back" to pure, radiometric output... Which in turn, makes spectral distribution graphs useful again.

PetFlora said:

In theory all this info is great, so then, tell me why my clones are growing like crazy under ONE EcoSmart (FEIT) 22w 5000K (1600 lumens). 3 days ago I added one 17w Philips RP 3000K. What does Intensity (or supposed lack thereof) have to do with it?
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Sorry Pet - I don't see what the relevance of this is?

PetFlora said:

In theory all this info is great, so then, tell me why my clones are growing like crazy under ONE EcoSmart (FEIT) 22w 5000K (1600 lumens). 3 days ago I added one 17w Philips RP 3000K. What does Intensity (or supposed lack thereof) have to do with it?

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PF, this is vegging, flowering MJ is a different story

SnotBoogie said:

GS - i was puzzled when you were bashing the oslon WW for efficiency before

If cree give you the XTE's radiometric efficiency, or you sit down and do the math, do share - Im not planning on using XTE again soon, but i'd be curious what the stats are like on my existing XTE panel.

Click to expand...

I will try those WW CC, i should have one or two engines almost for free. But i'm very sceptic with SDS theory. I didn't say he is wrong. I will thinking about all he said and make my own opinion, asking to specialists and professionals for accurate datas in mW or PPF. Actually i agree with Jubiare. Phosphor layers decrease the efficiency. The lower the CCT, the lower the efficiency.

Lumen are related to human eye, yes, and human eye sees the green very well, and yellow and cyan, so the more cyan/green/yellow (green is the most important) in the spectrum the more the luminous flux in lm. When i see the XTE graph, it has green, yes, and cyan and yellow, and it is 131lm/W at 25°C. But the red peak is much bigger, this spectrum has relatively a lot more red than a oslon CC 2700K given at 89lm. As we said sooner, lumen are only useful to compare 2 leds of same CCT or spectrum. So when i compare the 2900K XTE graph with the 2700K LCW CC graph there is only 200K of difference, so lumens are representative of efficiency, so i would say that the XTE is more efficient, by far, and she has a better thermal resistance.

And when SDS says that plants are using all the wavelengths, maybe he is right, maybe green could be useful for flowering. When I tried NW+red spectrum i had very good results and this spectrum has principally blue/green/red and hyper red, and it worked.

I know that all strains don't like pure blue/red spectrum (some do), and I sure that for flowering (all strains), the spectrum needs other wavelengths. I thought it was yellow/orange + far red and IR. Maybe green is more important than I thought. I will take it in consideration.

Anyhow I will know who is right soon about efficiency, i will wait for Osram's answer, if i don't have it, one friend has a led company, with integration sphere and everything to measure the radiant power. I should do it for free.

The thing i would like to know is to convert it to Micromoles (PPF), it is more important for us than Watts, the energy carried by a photon is related to its wavelength.

I too not disregard STS theories/facts..

What it seems to me, tech is going towards higher CRI for rendering luminaries more adaptable to the human eye, which isn't necessarily good for growing hmmm...

I mean it depends.. If you supplement your monochromatics with whites all right, but if you mainly utilise whites..

But than again, the sun is also 100 CRI at times during the day

We'll "see"

jubiare said:

Snoot....dont be so sure about it

The concept of using a color mix to achieve high CRI and high efficacy in warm-white SSL products came originally from Cree in the True White products. More recently, Osram Opto Semiconductors has supported the concept with its Brilliant Mix technology.

"In any case, the idea is to use red or amber LEDs to add spectral power in the visible red wavelengths in an efficient manner. Phosphors that can deliver such wavelengths are generally inefficient because they also generate energy that falls outside the human-visible spectrum, thereby wasting energy"

"That's been my observation as well. The CRI is higher because of the boost in Cyan output. The standard warm emitter always looked very pink because of it's high Red output. The higher Cyan in the HCRI counteracts this and the colour is much more balanced, in my eyes at least"

...according to this, higher CRI is accomplished to blend in more than just the red?

Click to expand...

Now you are referring to human vision .....
And it's all correct ....

But for plant growth .....


"In any case, the idea is to use red or amber LEDs to add spectral power in the visible red wavelengths in an efficient manner. Phosphors that can deliver such wavelengths are generally inefficient because they also generate energy that falls outside the human-visible spectrum, thereby wasting energy"

Yes ! Exactly ! At the range 700~750nm ..
Which plants utilise enough .....
( Phytochrome-Emerson effect !!!! )

Wasted energy for human vision applications ,useful energy for horticultural purposes ..!!!!


So .....Sould we rephrase that ,into ....

Phosphors that can deliver such wavelengths are generally efficient ,for plant growth !!!

Yeah that's right, so the high CRI isn't good and the old tech WW was a better one for"us"? (Purer red employed with no cyan etc)
Anyway..
Greensurfer
Looking forward to what your sources says when they get back to you

The thing i would like to know is to convert it to Micromoles (PPF), it is more important for us than Watts, the energy carried by a photon is related to its wavelength.

Click to expand...

infos and calculators can be found here...

http://www.pveducation.org/pvcdrom/properties-of-sunlight/photon-flux

green surfer said:

PF, this is vegging, flowering MJ is a different story



I will try those WW CC, i should have one or two engines almost for free. But i'm very sceptic with SDS theory. I didn't say he is wrong. I will thinking about all he said and make my own opinion, asking to specialists and professionals for accurate datas in mW or PPF. Actually i agree with Jubiare. Phosphor layers decrease the efficiency. The lower the CCT, the lower the efficiency.
Which of two ? The radiometric or the photometric efficiency are you referring to ?
Cause impact of red phosphor layer in RADIOMETRIC efficiency is rather detrimental , as opposed to impact at the photometric one ...

Lumen are related to human eye, yes, and human eye sees the green very well, and yellow and cyan, so the more cyan/green/yellow (green is the most important) in the spectrum the more the luminous flux in lm. When i see the XTE graph, it has green, yes, and cyan and yellow, and it is 131lm/W at 25°C. But the red peak is much bigger,
???? Look closely ....


this spectrum has relatively a lot more red than a oslon CC 2700K given at 89lm.

No Way !!!!
More Ambers yes ..Reds ,NO! ..... BY ALL MEANS NO !!!!

* 1 *


As we said sooner, lumen are only useful to compare 2 leds of same CCT

^^^NO ! FAR FROM TRUTH !!!

or spectrum.
^^^YES ,ONLY AT THAT CASE.WITH THE EXACT SAME SPECTRUM,nm for nm !!! !!

So when i compare the 2900K XTE graph with the 2700K LCW CC graph there is only 200K of difference, so lumens are representative of efficiency,
^^^^NO ! FAR FROM TRUTH !!! Not for real power efficiency ...
so i would say that the XTE is more efficient, by far, and she has a better thermal resistance.
^^^Maybe yes ,maybe no ....Thermal Resistance is not enough ,by itself,to judge a led's efficiency ....

And when SDS says that plants are using all the wavelengths, maybe he is right, maybe green could be useful for flowering. When I tried NW+red spectrum i had very good results and this spectrum has principally blue/green/red and hyper red, and it worked.

I'm not the one saying that ..Plants ,do ....(Along with many scientists and modern researches ..)

I know that all strains don't like pure blue/red spectrum (some do), and I sure that for flowering (all strains), the spectrum needs other wavelengths. I thought it was yellow/orange + far red and IR. Maybe green is more important than I thought. I will take it in consideration.

Anyhow I will know who is right soon about efficiency, i will wait for Osram's answer, if i don't have it, one friend has a led company, with integration sphere and everything to measure the radiant power. I should do it for free.

The thing i would like to know is to convert it to Micromoles (PPF), it is more important for us than Watts, the energy carried by a photon is related to its wavelength.
Here ....=> (* For 1 Watt of flux,per nm ...)

I.e 1 Watt of light at 600nm is ~ 5 umoles/sec

Or .... 1 Watt of light of x wavelength = x ( nm ) / 119.708 umoles/sec ......

Click to expand...

......................................

jubiare said:

Yeah that's right, so the high CRI isn't good and the old tech WW was a better one for"us"? (Purer red employed with no cyan etc)
Anyway..
Greensurfer
Looking forward to what your sources says when they get back to you

Click to expand...

The other way around in fact ....

*1* for post #115 ...


Human vision brightness sensitivity graph ( CIE standard )



The green line is average human eye sensitivity at full light conditions ..
( Retinal RGB cones,fully activated )


The photopic one ....


1 = 683 lm .....

Red peak of XTE WW 2600 K , being at ~ 610 nm
Red peak of Oslon WW 2700 K , being at ~ 630 nm

One Watt red at 610 nm = 0.6 * 683 = ~410 lm ..
One Watt red at 630 nm = 0.4 * 683 = ~270 lm ..

Output flux =same ...(same radiometric -'real'- power )= 1 Watt

Peak difference = 20 nm (* a mere 20 nm .... )

Photometric power difference = a whopping ~ 140 lm ....

So....If both leds have a peak at their reds/ambers of ~ 100 mW ....
Just from that 20nm peak difference ,XTE already has ~14 lumens more ,than the Oslon ..
FOR SAME OUTPUT RADIOMETRIC POWER, AT THEIR PEAK WAVELENGTH ( having " 1 " at REL .POWER =RED /AMBER PEAKS ..)

Just from one single wavelength !!!!!! 14 lumens difference !!!!!

Need more to understand that simple thing ?


It's everybodys right to think that the 'lumens' unit ,
does have an use in horticulture ....

Truth is ,way ,different though..

But , live in your "myth" if you like ..
You're free to do so ....

I prefer the truth ...

interesting, the difference of colour sensitivity perception in low-light....

I always think of my night-sight as "black and white"...

Will have to wait til tonight to test i guess

edit2: answered my own question...

"The behavior of the rhodopsin photopigment explains why the human eye cannot resolve lights with different spectral power distributions under low light. The reaction of this single photopigment will give the same quanta for 400nm light and 700nm light. Therefore, this photopigment only maps the rate of absorption and does not encode information about the relative spectral composition of the light. [SUP][5]"
[/SUP]
edit: OHHH...so that is why you can watch nocturnal animals with deep red light, and not disturb them.. Rod cells (low light vision cells) are completely (>??) insensitive to light over ~640nm.... Maybe im taking a panel outside LOL

SnotBoogie said:

interesting, the difference of colour sensitivity perception in low-light....

I always think of my night-sight as "black and white"...

Will have to wait til tonight to test i guess

edit2: answered my own question...

"The behavior of the rhodopsinphotopigment explains why the human eye cannot resolve lights with different spectral power distributions under low light. The reaction of this single photopigment will give the same quanta for 400nm light and 700nm light. Therefore, this photopigment only maps the rate of absorption and does not encode information about the relative spectral composition of the light. [SUP][5]"
[/SUP]
edit: OHHH...so that is why you can watch nocturnal animals with deep red light, and not disturb them.. Rod cells (low light vision cells) are completely (>??) insensitive to light over ~640nm.... Maybe im taking a panel outside LOL

Click to expand...

That's why jet fighter pilots ,use red goggles inside their helmet ...
Not to "loose" vision ability ,when passing from bright light to darkness ( i.e . clouds ) and vice versa ...

Using red light at night ,does not "spoil" vision's acclimatised state to darkness ..
(military map reading light ... )
At darkness ,we see cyan light as brighter ...( scotopic curve ) .....

Well pertaining our discussion there's no one person believing that lumens are how we look at growing

So the truth is yours and the myths are ours?

Also who says that xte peaks at 610.. The general graph of the warm whites?

Again you are so sure about things as usual sts

Like when you were completely dismissing hyper reds do you remember? And now you use them in your light

Sorry but your explanation doesn't convince me at all you can't call it ultimate truth, and I believe in photons not in lumens as always

Guod
What do you say on the whole thing?