25% more yield with a diffused LED ?

[exploziv]

Riiiiight...
So if the tops get less light this means also the lower growth gets less light.
The net photons are reduced by 7%, so why not just raise the light by 10% of distance from tops?
I have serious doubts about how this issue gets pictured here...

Cheers

Working on that logic, why not dim the light by 10% and keep it same distance? And you pocket the economy in electricity. The plants might be happier too! Certainly helps to find the sweetspot for all factors, I feel we are just starting to play with the data.. future should be bright.

 

[GoatCheese]

Riiiiight...
So if the tops get less light this means also the lower growth gets less light.
The net photons are reduced by 7%, so why not just raise the light by 10% of distance from tops?
I have serious doubts about how this issue gets pictured here...

Cheers

LOL ..you have trouble understanding what you’re reading, Koonsy.
I clearly wrote that i lowered the light fixture after putting the diffusers on it.

Take a light meter and see what happens when you LOWER the light ...i bet the reading goes up.

Proper comedy! ..you clearly are on a mission to make yourself look like a complete moron.

Diffusers definitely work!

I got the diffuser strips installed on my small veg/bloom light yesterday and the improvement is very clear. I can now keep the light much closer to the plants without seeing stress symptoms- without the tops dehydrating.

According to the shop where i got these strips the light transmittance is 93%= you will lose 7% of the light
..but i can now keep the light atleast 20% closer to the plants and it’s quite clear the plants/tops are getting more light now.

:

:

Some of you seem to have serious problems comprehending the heat radiation part of these photon beams! How thick do you have to be to go week after week about the same BS and still not getting it?!

How many times have i written about it in this thread - heat radiation dehydrating plant tissue/photons acting as heat radiation carriers. ..it must be close to ten times by now, and all some of you talk about is LIGHT.
What ever..

For me the diffusers helped – you guys do what ever you want.

I’m outski. This is just waste of my time.

 

[Koondense]

GoatCheese, if it helped you, then I'm happy for you.
Everything else is useless, no need to explain

Working on that logic, why not dim the light by 10% and keep it same distance? And you pocket the economy in electricity. The plants might be happier too! Certainly helps to find the sweetspot for all factors, I feel we are just starting to play with the data.. future should be bright.

Because dimming by 10% will reduce the intensity at low sites by more than 10%.
I'm "advocating" the idea that the sun's constant gradient is best for cannabis, so (multiple)point source at high distance to me feels better than same light from every direction.
The premise of this thread is like saying that greenhouse light is better than open sky light(I believe it's the opposite).

Cheers

 

[Ca++]

I have clear covers over my cobs. I wouldn't call them diffusers though. They are clear. Mechanical protection to stop me shoving my plants into the lights when I lift them.

 

[Cerathule]

Maybe we could first talk and agree about the meaning of words used to avoid any future misunderstanding.
For me, radiative heat are photons in the IR regions in contrast to "light" which are photons visible to the human eye 360-750nm.
IR is way better suitable to transfer its energy to matter due to the way it interacts with molecules. Paradoxically an IR photons carries way less energy than a light photons which is why IR heaters heat better than an LED growlight as the IR heater can create far more photons from the same amount of electricity used.

Some argue that the same watts burned equates to the same heat but that is not correct. Photon interaction with matter can cause other things like chemical reactions where the energy released is stored without increasing the temperature of a system.

 

[Cerathule]

The premise of this thread is like saying that greenhouse light is better than open sky light(I believe it's the opposite).

Direct sunlight is too strong for many species and plants developed many strategies to cope with some of the negative ramifications of that, esp. water conservation and protection of the core photosynthetic apparatus.
Greenhouses can help here by filtering some of the harsher or unneeded rays out, mostly UV & IR.

BUT... what you wrote earlier is also very correct, any reduction in total PPFD will result in less photons available deeper in the canopy, so there's also a loss associated with it. Some plants dwell foremostly within this shadelight. That's something actually undervalued I'd venture to say studies attribute a large fraction of annual biomass to it.

 

[Koondense]

Some plant species are more happy with less light, obviously for adaptation reasons.
But let's be real. Cannabis thrives in full sunlight, high mountain areas provide probably the best environment for certain type of selection(high cannabinoids).
Of course also cannabis adapts, some prefer it easier with everything... The point is management.
If you can manage the canopy you can grow under virtually any light, only thing is to understand the spectrum and intensity in your grow area. Anything can or can't work

Cheers

 

[Cerathule]

Some plant species are more happy with less light, obviously for adaptation reasons.

there's so many ways to skin this cat, but one way to look at it is how chloroplasts themselves react to +2000ppfd harsh UV/A/B and a boatload of heat radiation of full sunlight and they would fry if the species wouldn't have filter pigments and screens.
And that is true for all species because chloroplasts genetic remain virtually unchanged for long before plants made landfall half a billion year ago.

But you are right, Cannabis loves light, with elevated CO2 (like in prehistoric times) even more than now. The C3 plants are able to surpass the C4's in that regard at a certain stage.
But then there's also inbreeding depression & the indoor domestication syndrome. Some studies already measured specific medical strains can't even take half of ppfd sunlights offers.

 

[Cerathule]

The premise of this thread is like saying that greenhouse light is better than open sky light(I believe it's the opposite).

What do you think about the idea that photon flux/irradiance should be correlated to plant age/mass/height? Due to physiological reasons, and physical ones like diminished flux due to greater self-shade (as it grows larger)
It seems logical to me.
Now diffuse light is known to help light distribution which studies show to help gain biomass.

Tbh outside the sky itself gives off a fair amount of radiation, from all side, via Rayleigh-scattering etc. There may be sn optimal ratio of direct-vs-diffuse light if we orientate ourself at nature's situation.

 

[Ca++]

There are certain situations where diffuse light would be better, without having to think about it much at all. Perhaps we have a single plant in a tent that doesn't touch the walls. Over it, a cob with tight beam angle. That cob could light the center of the plant fully, while very little light came from the cob to the walls. Where the walls could reflect it down the sides of the plant. In such a case, we could spread the light with a diffuser. The top would then be lit less, and the walls more. In response to this we could lower the light or increase the power. In either case, the top could be as illuminated as before, but now the sides get more. The plant is lit from more angles, leading to greater penetration. It's a win.

I have a cob every 40cm for veg. Often the plants will reach them. At which point some plant matter is so close it's at ppfd-extreme. While other bits are then shaded. Yes, it's a bad setup, but diffuse covers for my cobs would help. I have power in reserve so no real loss. Just a little more heat.

That 120mm globe might offer me a few skull caps for dangling below my cobs. I think prismatic diffusers would have better light transmission, but also less mixing of the beams than full on diffuse.


IR heat radiation doesn't travel through much. I was going to pose a question for the interviews but wasn't sure. I was told dutch growers once puzzled over why poly beat glass. The answer was perhaps IR. It's just puzzle pieces which made my question incomplete so nonsensical. The root cause for my meanderings is IR doesn't pass through glass particularly well. It heats the glass, which then radiates IR. I experimented with this, putting glass between my hand and lit HIDs. For a moment the heat was gone. Then the glass warmed. In theory, the IR would heat the glass, which would radiate the heat from both sides. So the glass might offer a 50% reduction. The bits don't quite fit though, as some IR transmission is possible.
If you are thinking about IR lamps being glass, it's usually cold glass. A different type of glass, which is quite brittle. Used for dichroic hot & cold mirrors also. Now they really are something to get excited about. Until you see the price. Even the best studio's avoid it's use. Making astronomy lenses our source. A hot mirror lets through light, while reflecting IR. It's uncommon. While cold mirrors reflect light not IR, and you probably have one. Dichroic lamps.

I might buy some window frosting film. That might suit my app more.

 

[Koondense]

What do you think about the idea that photon flux/irradiance should be correlated to plant age/mass/height? Due to physiological reasons, and physical ones like diminished flux due to greater self-shade (as it grows larger)
It seems logical to me.
Now diffuse light is known to help light distribution which studies show to help gain biomass.

Tbh outside the sky itself gives off a fair amount of radiation, from all side, via Rayleigh-scattering etc. There may be sn optimal ratio of direct-vs-diffuse light if we orientate ourself at nature's situation.

Your point stands, imo. No need for full blast sun for a seedling, it correlates with leaf area which also correlates to plant age/dev stage/leaflets etc.
In a way diffuse lightning simulates the early light a low grown seedling gets, not directly from the top, more from sides and overall not so intense.
The blue light from scattering is pretty low intensity. We still cast strong shadows in full sunlight, a bit less with cloud cover.
And this is the point here, diffuse lightning gets a bit more photons in shaded parts of plants, making it more even and maybe useful for the kind of plants which need milder lightning.
Now think about selections. Most cannabis we know was selected under hps spectrum and light levels, so in a way we changed it fundamentally just with this. Its response to environment is what we select for, and the environment we provide is less and less natural, so in a way we are making little useless dogs out of wolves
For sure some poodle won't survive in the woods, same as a medical cut will get killed in summer sunshine.
Bad selection? Maybe.
Same goes for us, we adapted to live indoors and would probably die soon if stranded in nature.

Cheers

 

[goingrey]

The premise of this thread is like saying that greenhouse light is better than open sky light(I believe it's the opposite).

Well, that is what the greenhouse panel manufacturers claim in their marketing. Both in regards to diffusion and UV filtering.

Obviously not the most objective source. I would say that, "it depends".

 

[Cerathule]

Could the non-diffused colours somehow confuse the plants internally?

In nature outside they may get variations too but none these extreme

 

[JKD]

You shouldn't ever see the sun cause light bleaching. The problem isn't an excess of light. The problem is an excess of red when compared to the other colours. It can happen to cannabis at 800ppfd, if the right boxes are ticked. While 2500ppfd might be fine, in other circumstances. It's a recent study into excess red giving these numbers.

Bugbee saying essentially the same thing:

 

[Corpselover Fat]

I do have something eating at me. Evidence of beaming I can't (as yet) explain. Almost evidence of higher placement and diffusion helping. In an LED there is just one colour actually made, and the rest comes from a blend of different phosphors. On an atomic level, a single LED is in fact a number of different colour emitters. As what we perceive as colour, is actually different amounts of energy within individual photons, the idea of them blending, even as they travel from the sun, is ill founded. Physics has them down as particles.

What I'm seeing is much more tangible though. This is a gap in my curtains, letting light hit my tent floor. Yes it's carpeted.. and the gap is acting as shuttering, such that the rows of white and red LED's are painting there own lines from a QBs spacing. The light is a meter away.
View attachment 18721923
Why a meter from my light, do I still see the 660s light fall, away from the 3500k whites.

Here we are again with a bigger gap. I can't open it further as it washes out to barely noticeable.
View attachment 18721924
That is through some sparse plants which play a big part. There is separation there though. Which I just can't ignore or fathom at this time.

I'm sure @GMT will be along telling me to hoover soon. It's too good to miss




Edit: The fine lines might be nothing to do with the QB spacing, as it's not actually lined up with the gap. It's maybe 45 degrees off where you would place it trying to perform such an experiment. It's all quite boggling. It needs some thought, and is surely evidence of something..



Edit2: Perhaps in the top pic, the three red lines are actually from one row of reds. These boards are two red rows, the rest white. So this might be just shuttering, if it were not for the second pic. In any case, if a gap in the curtain can do this, a gap between leaves can.
If we move from curtains to leaves, then why not look at this atomically. Factor in what we know about more than 30% blue being bad, and think how a row of Blue LEDs would look beside the red ones. There is a picture forming.
There is a picture forming?

This effect is just from having multiple light sources and the light from them comes at different angles casting the shadows at different places.

 

[Cerathule]

Let's say if I were to place a number of monochromatic diodes close together on a heat-sink but now wish to have all the varying colours mix perfectly together before it is then released by the optic. What kind of extra lense hardware would be needed and how big is the loss of light from this approximately going to be?

 

[Koondense]

What would be the desired outcome of the system?
I'm not sure to understand what you mean with "a number of monochromatic diodes close together"(like different color diodes closely in a pattern?) and "varying colors mix perfectly together before it is then released by the optic". Theoretically it can sound like a point source white light
The trouble with optics can be dispersion of different colors so there will always be some uneven distribution. But this is a problem in telescopes and microscopes, not a problem in growing plants. Probably

Cheers

 

[Cerathule]

What would be the desired outcome of the system?
I'm not sure to understand what you mean with "a number of monochromatic diodes close together"(like different color diodes closely in a pattern?) and "varying colors mix perfectly together before it is then released by the optic". Theoretically it can sound like a point source white light
The trouble with optics can be dispersion of different colors so there will always be some uneven distribution. But this is a problem in telescopes and microscopes, not a problem in growing plants. Probably

Cheers

A SPD consisting of a carefully weighted colours like 1-2 blue, 1 orange, 8 reds, 1 darkred monochromatic diodes.
Now a lense (or whatever) to mix these colours evenly/perfectly.
I wonder how that could be done best? I'm thinking a 2-step diffusor screen, where the 2 plates are separated by a perfectly deflecting chamber in between them?

 

[Koondense]

So the goal is that every point on the illuminated surface gets the same ratio of colors which are primarily emitted?
I would just avoid the diffuser and put the LEDs at max possible distance, with no individual lenses on LEDs. Maybe some reflector to concentrate the beam. Also the mono led pattern should be small and repeated, not like in rows but organized like cells. Imo of course
Cheers

 

[Corpselover Fat]

A SPD consisting of a carefully weighted colours like 1-2 blue, 1 orange, 8 reds, 1 darkred monochromatic diodes.
Now a lense (or whatever) to mix these colours evenly/perfectly.
I wonder how that could be done best? I'm thinking a 2-step diffusor screen, where the 2 plates are separated by a perfectly deflecting chamber in between them?

You will just get those mono spikes even if you blend them, because that's all you had to begin with. The photons don't change in this scenario. They are just redirected. The different photons might be perfectly mixed and spread, but still only spikes on the spectrum. It would even look white to you, but the light would render colours badly.