New style Samsung LM561C Board

see4

Well-Known Member
Mixing CCT's is a fools game, TBH. You simply end up with an average of the two CCT's - in this instance, 3500K which is a readily available color temp. Stephen from HLG has posted some spectrometer measurements that showed this. The only time it makes sense is if you want to turn off the lower CCT diodes for Veg and then add them in during flower
A diode produces a specific light spectrum, two diodes of different spectrums do not make an average spectrum. A 3000k spectrum diode produces wavelengths beneficial to plants not found in 4000k and 3500k spectrums.
https://plantmethods.biomedcentral.com/articles/10.1186/1746-4811-8-46
 

Ryante55

Well-Known Member

ANC

Well-Known Member
What's the difference? They both have components that produce heat and require heat to be distributed away from the board.
It's an honest question, I don't know the answer, which is why I asked.
It is the amount of heat they produce. which is negligible. If you need to pass 250mW you use a 250mW resistor, for example. The board doesn't have to cool shit.

When you have a tiny, high Wattage component that degrades with temperature unlike say a metal foil in a capsule. You need to draw the temperature away into the copper where it can interface with the air.

You seem bored, help me find 1200 x 40mm extruded heatsinks
 

see4

Well-Known Member
A 2012 article about colored diodes? Really? How does that help your argument this is a totally different tech.
Hm let see where see4 come's with this time.
3000K, 4000K et al are simply a kelvin value of color temperature which produce a range of lightwaves, measured in nanometers, ie. 450nm, 640nm, etc.
Mixing diodes that produce 640nm lightwaves and 450nm lightwaves respectively do not produce 545nm lightwaves. It produces 640nm and 450nm lightwaves respectively.
The article was meant to highlight that mixing lightwaves, measured in nanometers does not produce averaged lightwaves, but rather a mix.
 

see4

Well-Known Member
It is the amount of heat they produce. which is negligible. If you need to pass 250mW you use a 250mW resistor, for example. The board doesn't have to cool shit.

When you have a tiny, high Wattage component that degrades with temperature unlike say a metal foil in a capsule. You need to draw the temperature away into the copper where it can interface with the air.

You seem bored, help me find 1200 x 40mm extruded heatsinks
Ok, that makes sense. So putting a heatsink on the back of the boards helps draw the heat away, thus somewhat negating the effect heat will have on the efficiency of the diodes.
Which is what I presumed, and is why I bought heatsinks to go with the boards I bought.
upload_2018-1-2_12-20-54.png
 

paraordnance

Well-Known Member
Yes, that is true - but the inverse square function is basically useless for making such predictions with multiple emitters and reflective walls.

Mixing CCT's is a fools game, TBH. You simply end up with an average of the two CCT's - in this instance, 3500K which is a readily available color temp. Stephen from HLG has posted some spectrometer measurements that showed this. The only time it makes sense is if you want to turn off the lower CCT diodes for Veg and then add them in during flower.
Dude you have no clue what you talking about. When you bash something at least have real experience not something you read online. I use 3000k, 4000k and 5000k COB fixtures and strips for growing and all 3 cct colors combined produce way better results than each one individually. I have them all on at the same time and the plants that under just 3000k visibly stretch a lot more than ones under 5000k & 3000k combined. So please don't spread unconfirmed BS.
 

nfhiggs

Well-Known Member
3000K, 4000K et al are simply a kelvin value of color temperature which produce a range of lightwaves, measured in nanometers, ie. 450nm, 640nm, etc.
Mixing diodes that produce 640nm lightwaves and 450nm lightwaves respectively do not produce 545nm lightwaves. It produces 640nm and 450nm lightwaves respectively.
The article was meant to highlight that mixing lightwaves, measured in nanometers does not produce averaged lightwaves, but rather a mix.
No it does not produce averaged lightwaves, it produces an averaged SPECTRUM. CCT describes a SPECTRUM, not individual lightwaves. Both CCTs produce lightwaves ALL ACROSS the visible spectrum (not just two frequencies), differing only by the amount of photons at various frequencies. it is the amount of photons produced at various bands that determine the CCT. As CCT increases the spectrum shifts towards the blue end.
 

nfhiggs

Well-Known Member
Dude you have no clue what you talking about. When you bash something at least have real experience not something you read online. I use 3000k, 4000k and 5000k COB fixtures and strips for growing and all 3 cct colors combined produce way better results than each one individually. I have them all on at the same time and the plants that under just 3000k visibly stretch a lot more than ones under 5000k & 3000k combined. So please don't spread unconfirmed BS.
I really don't care what your individual experience is, TBH. CCT is something that is easily measureable using a spectrometer.
 

see4

Well-Known Member
No it does not produce averaged lightwaves, it produces an averaged SPECTRUM. CCT describes a SPECTRUM, not individual lightwaves. Both CCTs produce lightwaves ALL ACROSS the visible spectrum (not just two frequencies), differing only by the amount of photons at various frequencies. it is the amount of photons produced at various bands that determine the CCT. As CCT increases the spectrum shifts towards the blue end.
I agree with you about your description of CCT.
Yes, they actually DO. Stephen has shown this using a spectrometer.
We simply don't agree.
Diode 1 produces 620nm light, diode 2 produces 480nm light, the plant will get both 620nm light and 480nm light, not 550nm light.

Edit: Actually, now that I've reread your description, some of it is accurate, other parts are not. CCTs, in this case 3000k and 4000k, do not produce lightwaves all across the visible spectrum. In fact, 3000k produces a fair amount of lightwaves, measured in nanometers, that are not visible to the human eye. (Assuming that is what you mean by visible) -- And that is precisely why I chose 3000k and 4000k diodes, to get the benefit of the far end red spectrum, while getting the benefit of far blue spectrum (that is not produced by 3000k diodes).
 
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nfhiggs

Well-Known Member
May be get some experience then come back
Maybe get some intelligence and then come back. This is simply not debatable, nor is it an opinion - it is a simple point of fact. CCT is determined by spectrum which is measurable with a spectrometer, and has been done by Stephen of HLG to demonstrate this exact fact.

You experience above merely shows that more blue reduces stretch - higher K means more blue. You can add blue by adding 5000K to 3000K, OR you can just use 4000K. Is it really that hard to figure out?
 

paraordnance

Well-Known Member
20180102_201431.jpg
Maybe get some intelligence and then come back. This is simply not debatable, nor is it an opinion - it is a simple point of fact. CCT is determined by spectrum which is measurable with a spectrometer, and has been done by Stephen of HLG to demonstrate this exact fact.

You experience above merely shows that more blue reduces stretch - higher K means more blue. You can add blue by adding 5000K to 3000K, OR you can just use 4000K. Is it really that hard to figure out?
No, you really are dumb, take a look at 5000k chart, 3000k and 4000k one, so you saying when they are combined make up 4000k no way. 5000k has more blues, which 4000k does not, same for far red, 4000k barely has any, when 3000k over 15% of the spectrum. So combining spectrums does not equal to median one, don't you get it?

This picture above shows all three mentioned spectrums and can be placed strategically to control plant height. Mixing them is advantageous if you can figure out how to use it to your space
 
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ANC

Well-Known Member
These modern cobs are so strong, you can easily mitigate stretching by bringing them a few inches closer. Don't need anything but 3k.

I'd rather fight over CRI, 90 CRI > 80 CRI
 

nfhiggs

Well-Known Member
I agree with you about your description of CCT.

We simply don't agree.
Diode 1 produces 620nm light, diode 2 produces 480nm light, the plant will get both 620nm light and 480nm light, not 550nm light.
Do you grasp the fact that monochrome light does not have a "CCT"? Your argument above makes no sense and does not apply in any way to combining WHITE LIGHT spectrums. You are in effect, pointing at rabbits while arguing about the existence of chickens.


Edit: Actually, now that I've reread your description, some of it is accurate, other parts are not. CCTs, in this case 3000k and 4000k, do not produce lightwaves all across the visible spectrum. In fact, 3000k produces a fair amount of lightwaves, measured in nanometers, that are not visible to the human eye. (Assuming that is what you mean by visible) -- And that is precisely why I chose 3000k and 4000k diodes, to get the benefit of the far end red spectrum, while getting the benefit of far blue spectrum (that is not produced by 3000k diodes).
Looking at curves is misleading. Sure it looks like you are just adding a chunk of red light from 640 - 700nm - but you are also adding everything on the curve that's below 640. Once the combined curve is re-normalized all you really have is a red peak shifted some. Again, at the risk of repeating myself, this is something that Stephen has actually measured with his spectrometer and posted. You don't really get anything that "wasn't" there, you just get more of EVERYTHING with the ratio shifted some. All of those red wavelengths from 640-700 ARE present (in the 400K), just not as much of them. if you want more far red, then just add far red, without all the rest of the spectrum that comes with a white diode.
 

see4

Well-Known Member
This is simply not debatable, nor is it an opinion - it is a simple point of fact. CCT is determined by spectrum which is measurable with a spectrometer, and has been done by Stephen of HLG to demonstrate this exact fact.
CCT does not equal wavelength (nm).
CCT is not "determined" by spectrum, it is merely a description/label of a spectrum.
A spectrum consists of many wavelengths (nm).
Mixing diodes of various spectrums, thusly various wavelengths, does not produce averaged wavelengths.
A 620nm wavelength and a 480nm wavelength do not make up a 550nm wavelength, they make up a 620nm wavelength and 480nm wavelength.

You ever have a black light on in a room with the light on? You don't really see much. Then when you turn the light off in the room, an entire world of magic opens up before your eyes.
Guess what? When the lights were on, the black light was still producing light! Imagine that! And at the very same wavelength!! Gasp! Shocker! :wink:
 

dabby duck

Well-Known Member
Indeed, the community at large wants to see higher CRI output from diodes/cobs.
No they dont... high cri was only relevant because it coincided with deeper reds but still a photon filter otherwise cri tends to be worthless for measuring radiometric output [read:non_quantifiable]. Newer gens like vero have gotten better but they still bottleneck photon delivery at the expense of red delivery....besides far red and far blue are still in much debate about in vitro physiology occuring....

Stardustsailor was right about then about low cri diodes and still now.....
 
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