Prawn Connery
Well-Known Member
I hate to say this to Kiwi, but Geeze I love your work!
High Light efficiency tests (TEKNIK) - 2.47 umol/j CRI 94.2
- Thread starter Prawn Connery
- Start date
Frank Cannon
Well-Known Member
Well I think your work may be ok too...
Frank Cannon
Well-Known Member
It's a Prawnlove fest
coreywebster
Well-Known Member
Randomblame
Well-Known Member
Today, unfortunately, nothing, brothers! I have the fuckin' flu, 39,5°C and I'm laying totally flat. No chance!
Sinuses are completely closed and I have headache like hell. Feels like foam in the nose which slowly expands ...
An eye is almost closed already and it's of course weekend! Men, I hate it!
Craziest shit, its the 1st time since 10 years or so I got it.
Wtf, we have already 20°C outside and I get the fucking cold.
Or_Gro
Well-Known Member
Sorry to hear it, hope you get back to your workshop soon...
Kiwis 1, Germs 0...,,
Greengenes707
Well-Known Member
You guys know that goniometers and sphere measure the same thing as far as total output. The readings are well within margin or error... ~0.005% variation??? So what are you guys talking about in "the test methods are why they differ?" Cause it's not.
How does anyone think they measure things differently and are somehow bias???
Gonio has more information with it that CAN be used, but doesn't have to be. So as far as it's total output and efficacy...they are identical...and that's because they are supposed to be. Total output is total output...and that's why BOTH show it the same...cause that's what it is.
That additional info gonios supply is where all that total light is going/coming from. This is what a sphere can't do. But doesn't change or lower or raise it's output. That is finite for all intents and purposes.
Here is a real world example...
Sphere...30,250 lm
Gonio...30,098.8 lm
As for this board....it uses higher CRI diode...why is anyone surprised it's not pushing the limits of output???...its just the nature of the beast working with high CRI chips.
They are a filtered spectrum, not a better light source.
Adding red to a 80cri will raise the CRI...BUT so will taking away/filtering yellow/green/blue.
How does anyone think they measure things differently and are somehow bias???
Gonio has more information with it that CAN be used, but doesn't have to be. So as far as it's total output and efficacy...they are identical...and that's because they are supposed to be. Total output is total output...and that's why BOTH show it the same...cause that's what it is.
That additional info gonios supply is where all that total light is going/coming from. This is what a sphere can't do. But doesn't change or lower or raise it's output. That is finite for all intents and purposes.
Here is a real world example...
Sphere...30,250 lm
Gonio...30,098.8 lm
As for this board....it uses higher CRI diode...why is anyone surprised it's not pushing the limits of output???...its just the nature of the beast working with high CRI chips.
They are a filtered spectrum, not a better light source.
Adding red to a 80cri will raise the CRI...BUT so will taking away/filtering yellow/green/blue.
Randomblame
Well-Known Member
Yepp, total output is total output but with a geniospectrometer you can factor in beam angles and distance and you can exactly measure how much light hits a certain surface area. Total output is just total output and says only how much light is produced at board level.
If you use for instance a simple PAR sensor to measure the light hitting the canopy(PAR map) you get ~0,4-0,5 lower numbers compared to total output, no?
PSUAGRO.
Well-Known Member
I think that's obvious about both being accurate efficiency tests, no one said otherwise? Gonio is a cheaper entry
No ul facility is throwing out their large spheres last I heard.: )
All white diodes are "filtered"
.....for your pleasure
Last edited:
Warpedpassage
Well-Known Member
Hello gg, nice to see u back!
Is it not a better light source if its giving you the preferable spectrum?
For example, When i look at the cree j series3500k+ , 80vs 90cri.It seems the 90 cri is only filtering out around 580-600. And for the trade it gives a very nice boost in 480-530, considerable more 610-730. So is that not a better light source? What do u think?
Hey random, hope u r feeling better!
Prawn Connery
Well-Known Member
My understanding is light is not "filtered" per se, but rather "converted", with subsequent radiometric losses that end up as heat instead of light.
Blue light (or ultraviolet, as in the case of SSC's Sunlike) is emitted at a constant wavelength. These waves of energy are absorbed by different phosphors (for simplicity green, red - and blue, in the case of violet pump LEDs), which are excited and change state, giving off radiation of a longer wavelength, thus converting "blue" light to green and yellow and/or red.
Shorter wavelengths contain more energy. When absorbed and re-emitted as longer wavelengths, the difference in energy is expressed as heat. This is where efficiency is lost.
Some of the original blue (or violet) light passes through the phosphor and is not absorbed, and therefor continues on its way as the original blue spectrum. Which is why blue pump LEDs have a large blue spike, and the remainder is absorbed and re-emitted as green (including yellow) and red.
To get high CRI LEDs, you need to shift some green-yellow to red, and it also helps to broaden the visible spectrum. I don't pretend to know much more about it than that. All I know is that when comparing CRI70, 80, 90, 95, 98 etc LEDs, you tend to see a progressive shift towards the red end of the spectrum at the sacrifice of green and yellow.
More red and less green-yellow obviously hurts luminous output (in terms of the way humans perceive "brightness"). Converting more blue light to red also results in less efficiency, as the energy discrepancy between short-wave and longer wavelength light increases.
The tradeoff is that plants photosynthesis longer wavelengths more efficiently, with red considered the most efficient in terms of quantum yield (amount of energy converted to leaf mass). Here's one such study: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6095554/
There's plenty of info on this site and elsewhere as to the differences in photosynthetic efficiency of blue, green and red light, but the short answer is, predominantly red, mixed with some green and some blue, consistently produces the best results - with the ratio of green-red less important than the ratio of blue to green-red.
It also depends on the species of plant, but red is even more important in flowering and fruiting species, than in leafy greens (in terms of end yield: flowers/fruit vs leaf mass).
The real question is: is the sacrifice in efficiency in high CRI or warmer kelvin LEDs offset by the increased efficiency of photosynthesis?
For what we've seen - at least, in cannabis - the answer is, higher CRI (not strictly the higher CRI, but rather the red shift) appears to produce the same or higher yields in less time than lower CRI (or "bluer") LEDs.
We've been observing this phenomenon since the old MH vs HPS days. These days we also have CMH, but by all accounts, HPS still outyields CMH. Where CMH and MH have an advantage over HPS is in UVA/B output, which increases oil (terpene) and cannabinoid production. For this reason, a lot of old-time commercial growers used to mix HPS and MH at a ratio of about 2:1, and to this day, many growers still mix HPS with CMH.
Back to high CRI, there is also an argument that full-spectrum LED targets more photoreceptors on the plant, which drives photosynthesis more efficiently. So the more "even" the spectrum, the more light energy the plant can use. As we all know, sunlight has a very even spectrum with no real peaks and troughs like you see with LED, HID and fluorescent lights etc.
boilingoil
Well-Known Member
https://docs.r4photobiology.info/articles/sun-article.nb.html.
Many things effect the spectral output from the sun.
OLD MOTHER SATIVA
Well-Known Member
like time of day.."she a changin alla time Mon"
Randomblame
Well-Known Member
The differences in efficiency are relatively simple to explain if you look at the parts used to create these yellow phosphor layers on white LED's. These phosphor pigments used in this layers are available in many different colors from dark blue to deep-red. Red pigments are for instance available in steps á 5nm from 625-660nm. And the same goes for orange, yellow, green and blue.
To get CRI90 and higher you need simply more control over the converted wavelengths, you need to add more of this phosphor pigments to cover a wider range of wavelengths and so you end up getting a higher pigment density in high CRI phosphors. CRI80 has for instance less to no phosphors in the cyan range and therefor a deeper cyan hole.
To get CRI90 and higher you need simply more control over the converted wavelengths, you need to add more of this phosphor pigments to cover a wider range of wavelengths and so you end up getting a higher pigment density in high CRI phosphors. CRI80 has for instance less to no phosphors in the cyan range and therefor a deeper cyan hole.
Last edited:
Greengenes707
Well-Known Member
Read below from page 1...I think that's obvious about both being accurate efficiency tests, no one said otherwise? Gonio is a cheaper entry
No ul facility is throwing out their large spheres last I heard.: )
All white diodes are "filtered"
Prawn Connery
Well-Known Member
Yes. But that's not really the point I was making.
The spectrum of light that reaches earth does change throughout the day, seasons, latitudes and topography etc. What doesn't change is that - no matter the weighting and ratios of each wavelength - the spectral curve of sunlight is relatively flat, with no substantial peaks or troughs compared to most LED and HID lighting.
In other words, wavelengths don't go "missing" or suddenly spike as atmospheric influences alter the spectrum - unlike LEDs and HIDs, which have lots of peaks (overweighting) and troughs (underweighting) in their spectra by design.
With sunlight, ALL wavelengths in the PAR spectrum are covered. And it is the weighting of those wavelengths and their ratios to each other that affects plant growth - especially if you believe plants have been tuned (evolved) to those hourly, daily and seasonal changes to make use of (photosynthesise) different spectra as they become more or less available throughout the day.
For example, are individual photoreceptors rested during some parts of the day to become more active during others when there is more or less red, green and blue light? And should we be trying to emulate this indoors by altering spectra at different times of the lighting schedule?
Or is it enough to simply "fill in the gaps" so that we have a reasonably smooth spectral curve?
Is it also the reason why plants seem to respond better to full spectrum light (with certain weightings of red, green and blue) than to narrow (targetted) spectra such as "blurple" etc?
I mean, mother nature's been around a lot longer than we have. Should we be paying more attention to her?
Randomblame
Well-Known Member
Yeah, I still say the same. Tested on the same test rig(teknik's) with the same parameters, distance and so I don't think there is such a big difference. Its for sure better efficiency with CRI80 but the gap should be lower. Especially when measured from 380-780nm like in this tests.
Maybe we will see some QB tests soon too cause he told me something like that.