I believe plants will give there best results under a developed spectrum, I don't think you would get much of a yield under a pure green light lol.
80% intensity 20% spectrum hmmmmm? I would like to see specific test data to believe this.
Lighting Bilbo's Brief Guide to Choosing Your LED.
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I believe plants will give there best results under a developed spectrum, I don't think you would get much of a yield under a pure green light lol.
80% intensity 20% spectrum hmmmmm? I would like to see specific test data to believe this.
the science says that IF you could make a light that was totally diffuse, then it would be the best light...that's why something we're working with now could prove beneficial...
However, in terms of relative intensity a lumen meter will give higher numbers in the visible spectrum, and lower number in the pure photosynthetic activity spectrum of blue and reds. That is why lumens mean very little to plants. PAR on its own is a reasonable measure, but only combined with spectrum. I can get huge PAR numbers from an HPS if I manipulate it right...likewise I can totally screw just about anything with a umol of well over 6000 with LED at source...our standard single 75W red blue at source is well over 1300umol...but source or single figures mean nothing.
A fully mixed light with no hotspots should be the aim, again, we have lab models but it's hugely difficult to get intensity and power evenly across a full surface without edge lighting, and edge lighting for LED is almost impossible when you have to include lots of wavelengths due to the colours you need to introduce. We have a system which works, but you need a 500W driver and a computer to run it as well as lots of other bits of kit...it's interesting, but couldn't be used in a consumer or even commercial setting. The diffusion surface on its own costs as much as all the other kit inside the light...
We also have warm white panels, cold white panels and neutral white panels which is the one we are tweaking with to get optimum spectrum from...and we grow things under all of them, and they perform...adequately...better than HiD usually anyway...BUT, spectrum is not correct, so you grow a different shape of plant and get differing results from what is considered normal...different tastes, different textures, lots of small changes...and we've found that white shifts more in the spectrum range than anything else. We're working on rectifying some of these issues...we might have a solution in the next year or so, but we are one of very few working on this...most work is being done on red blue spectrum.
So I think in order to answer the power v spectrum question is very difficult, you need to have the power (which is why we don't use weedy single diodes) you have to mix them (which is why we use a collection chamber and an optical lens) and you have to evenly get the resulting light onto the plant.
THE PLANT works with what it is given...and only a grower can interpret if that is what they require...straight cucumbers anyone?
However, in terms of relative intensity a lumen meter will give higher numbers in the visible spectrum, and lower number in the pure photosynthetic activity spectrum of blue and reds. That is why lumens mean very little to plants. PAR on its own is a reasonable measure, but only combined with spectrum. I can get huge PAR numbers from an HPS if I manipulate it right...likewise I can totally screw just about anything with a umol of well over 6000 with LED at source...our standard single 75W red blue at source is well over 1300umol...but source or single figures mean nothing.
A fully mixed light with no hotspots should be the aim, again, we have lab models but it's hugely difficult to get intensity and power evenly across a full surface without edge lighting, and edge lighting for LED is almost impossible when you have to include lots of wavelengths due to the colours you need to introduce. We have a system which works, but you need a 500W driver and a computer to run it as well as lots of other bits of kit...it's interesting, but couldn't be used in a consumer or even commercial setting. The diffusion surface on its own costs as much as all the other kit inside the light...
We also have warm white panels, cold white panels and neutral white panels which is the one we are tweaking with to get optimum spectrum from...and we grow things under all of them, and they perform...adequately...better than HiD usually anyway...BUT, spectrum is not correct, so you grow a different shape of plant and get differing results from what is considered normal...different tastes, different textures, lots of small changes...and we've found that white shifts more in the spectrum range than anything else. We're working on rectifying some of these issues...we might have a solution in the next year or so, but we are one of very few working on this...most work is being done on red blue spectrum.
So I think in order to answer the power v spectrum question is very difficult, you need to have the power (which is why we don't use weedy single diodes) you have to mix them (which is why we use a collection chamber and an optical lens) and you have to evenly get the resulting light onto the plant.
THE PLANT works with what it is given...and only a grower can interpret if that is what they require...straight cucumbers anyone?
Yozhik
INTJ & Non-Violent Domestic Extremist
Hi Xagor
typically white spectrum degenerates slightly more quickly than most colours. Something about the dope most manufacturers uses, ALL LED breaks down over time, but an awful lot of cheaper white, (of which there are huge amounts) degenerates at an alarming rate, the resultant shift in overall spectrum is quite alarming but not very noticeable to the human eye.
We've seen many white chips from many well known sources that have broken down completely inside 3 years. High CRI chips tend to perform better, especially Gan on GaN chips (such as those from Soraa), but overall, white is subject to the most degradation.
typically white spectrum degenerates slightly more quickly than most colours. Something about the dope most manufacturers uses, ALL LED breaks down over time, but an awful lot of cheaper white, (of which there are huge amounts) degenerates at an alarming rate, the resultant shift in overall spectrum is quite alarming but not very noticeable to the human eye.
We've seen many white chips from many well known sources that have broken down completely inside 3 years. High CRI chips tend to perform better, especially Gan on GaN chips (such as those from Soraa), but overall, white is subject to the most degradation.
Hi,
But heat and driving parameters are an issue. Id say: never run a chip near its max rated current. But the opposite is beeing done e.g. with those "3W led" Panels -they usually run near their max at about 2,2W for white/blue and 2W for red.
For cree cobs/leds you can find this, their lab results for long term lumenmaintenance and spectrum shift:
http://www.cree.com/~/media/Files/C...Lamp/XLamp Application Notes/LM80_Results.pdf
Im no expert, but those numbers look good to me. And while they give their result for 105°C or 85°C and pretty high currents-put on a nice heatsink, with reasonable currents, with active cooling Tj gets about 55°C -there is no need to worry at all.
If I could make a suggestion for your RnD atleast for MJ grow lights with no additional sunlight, test some CXB3070/ CXB3590 3000K or better 3500K high bin 80CRI at about 50W. (this ww also looks totally different to what you have on ur hp as ww) I think you will be very impressed. Or just one chip for ur light measuring device at about 1,4Amps or less.
Or more budget oriented with Vero29 V2 chips.
Color mix doesnt get better then with white/ 1 type of chip that does it all, does it?
Is there any white cob available thats better then a 3590? I mean in a reasonable way -not some secret lab 99% efficiency 100K$ way.
I think I read that those chips become more blueish with degeneration. But emphasis on "cheaper" white.
But heat and driving parameters are an issue. Id say: never run a chip near its max rated current. But the opposite is beeing done e.g. with those "3W led" Panels -they usually run near their max at about 2,2W for white/blue and 2W for red.
For cree cobs/leds you can find this, their lab results for long term lumenmaintenance and spectrum shift:
http://www.cree.com/~/media/Files/C...Lamp/XLamp Application Notes/LM80_Results.pdf
Im no expert, but those numbers look good to me. And while they give their result for 105°C or 85°C and pretty high currents-put on a nice heatsink, with reasonable currents, with active cooling Tj gets about 55°C -there is no need to worry at all.
But they are significantly worse in photon output per W (regarding common blue + phosphor) and maybe even too much gets wasted as FR.
But for MJ, neutral or cool white tends to prolong the flowering time, compared to ww.
If I could make a suggestion for your RnD atleast for MJ grow lights with no additional sunlight, test some CXB3070/ CXB3590 3000K or better 3500K high bin 80CRI at about 50W. (this ww also looks totally different to what you have on ur hp as ww) I think you will be very impressed. Or just one chip for ur light measuring device at about 1,4Amps or less.
Or more budget oriented with Vero29 V2 chips.
Color mix doesnt get better then with white/ 1 type of chip that does it all, does it?
Is there any white cob available thats better then a 3590? I mean in a reasonable way -not some secret lab 99% efficiency 100K$ way.
Last edited:
Just something perhaps a little
but then again maybe not.......I received below mail today
Hello,
I heard about this webinar in a meeting with our research team and thought you might be interested.
Dr. Youbin Zheng Talks Greenhouse LEDs in Free Webinar
One of LumiGrow's research partners, Dr. Youbin Zheng, Associate Professor at the University of Guelph and the Environmental Horticulture Chair of Vineland Research and Innovation Centre, shares his knowledge and experience using LEDs in the greenhouse in a free webinar September 17 at 2 p.m. EDT.
In this webinar, Dr. Zheng will cover the basics of LED technologies, including the historical development of LEDs as relates to energy efficiency and production costs, the advantages and disadvantages of employing LEDs for horticultural purposes, examples of current and upcoming LED applications in greenhouse crop production, and will share some of the latest research — including that which he has conducted in conjunction with LumiGrow.
Register online ››
As a reminder, LumiGrow is currently offering a Cash for Clunkers program. You can receive $50 off the purchase price of a LumiGrow LED light for each HID (or other technology) fixture you replace. Call / email me or visit our website for details. I'm happy to help!
Best regards,
Neil Coppinger
Vice President, Sales
LumiGrow, Inc.
(800) 514-0487, ext. 105
(415) 225-3948
ncoppinger@lumigrow.com
www.lumigrow.com
Hello,
I heard about this webinar in a meeting with our research team and thought you might be interested.
Dr. Youbin Zheng Talks Greenhouse LEDs in Free Webinar
One of LumiGrow's research partners, Dr. Youbin Zheng, Associate Professor at the University of Guelph and the Environmental Horticulture Chair of Vineland Research and Innovation Centre, shares his knowledge and experience using LEDs in the greenhouse in a free webinar September 17 at 2 p.m. EDT.
In this webinar, Dr. Zheng will cover the basics of LED technologies, including the historical development of LEDs as relates to energy efficiency and production costs, the advantages and disadvantages of employing LEDs for horticultural purposes, examples of current and upcoming LED applications in greenhouse crop production, and will share some of the latest research — including that which he has conducted in conjunction with LumiGrow.
Register online ››
As a reminder, LumiGrow is currently offering a Cash for Clunkers program. You can receive $50 off the purchase price of a LumiGrow LED light for each HID (or other technology) fixture you replace. Call / email me or visit our website for details. I'm happy to help!
Best regards,
Neil Coppinger
Vice President, Sales
LumiGrow, Inc.
(800) 514-0487, ext. 105
(415) 225-3948
ncoppinger@lumigrow.com
www.lumigrow.com
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