Light Intensity; LED vs HID

[BM9AGS]

oh goodness I fucking give up try to help somebody and all I see are rocks in the head.




GET OFF OF THE CALCULATOR AND STEP BACK AND LOOK AT WHAT YOU ARE SAYING

Look up the difference between PPF and PPFD and account for the overlap in multiple smaller sources AT THE SAME AMOUNT OF TOTAL LIGHT and OVERLAP between multiple point sources.

Fucking pussy ass quitter!!!

 

[PurpleBuz]

ha ha guess its true, a picture is worth a 1000 words

btw if you stop whackin, your weed might grow some monster colas lol just funin

 

[BM9AGS]

ha ha guess its true, a picture is worth a 1000 words

btw if you stop whackin, your weed might grow some monster colas lol just funin

I gotta woman that takes care of that.....

 

[OneHitDone]

There is like a 3rd dimension you boys are all missing which is intensity I believe expressed as "watts". Something like the velocity of photons leaving the source or something like that but I'm too much of a dumbass to properly explain it or put any Disneyland math to it

oh i get it

this

View attachment 3715272



penetrates better than this


View attachment 3715273



even though the same amount of photons are being released?


cool thread dude, can you start one about how magnets can be used to increase yield?

You are demonstrating better "coverage" but you will still have Fluffer buds down low vs the higher intensity single fixture where it is making it through

 

[PurpleBuz]

Something like the velocity of photons leaving the source

The speed of light is a constant.

overlapping light provides the same intensity provided the total amount of light is the same.

myth busted.

 

[Hybridway]

Totally agree!!! But you still gotta factor in that if you used 1000 watts of cobs they'd be spread out where as the HID filament is all in one spot. So with all the cobs touching and say out to a 20 inch by 20 inch square it's not the same comparison.


. But that's only one example and who the hell would have a single plant under a 4 foot by 4 foot LED light that's under driven. That would be a waste.

ME,ME, that would be me! Lol!

 

[JorgeGonzales]

cool thread dude, can you start one about how magnets can be used to increase yield?

 

[Hybridway]

no your not interpreting it correctly.

-assume I have a single point light source that provides 1000 umoles.
-assume further that its set at a height to distribute its light over a 5x5 area with minimal wasted light going up or sideways, using the inverse square law to estimate height from the top of the canopy.

-assume that you haave 4 point sources of light that are 250 umoles each.
-assume that you spread out the four lights to cover the 5x5 area with minimal wasted light using the inverse square law and evenly overlap between the four different point sources.

The 4 point sources of light will penetrate deeper and provide more even coverage than a single large point source for the 5x5 area

But you'll never have the intensity in any one spot to grow bud... In this case, the entire crop woukd suffer of low yield.
Under driving & spreading out is only good if your at least achieving a high enough PPFD to grow marijuana.
For ex: growing with any HPS under 600 w spread out or not, is a waste. So, why do the same with our COBs.
Why don't people grow with them at 70watts
Instead of 50? The yeild increase will be much greater then the electric loss.
I'm no fan of under driving if it's going to cause me to grow under 900-1200 umols on top.
All about spreading the light out but it has to be intense enough to begin with rather then spreading outrage same intensity. I took this to the extreme & now understand better.

 

[churchhaze]

velocity of photons leaving the source

Um...... You mean the speed of light? You couldn't be more off base with this one!

 

[PurpleBuz]

But you'll never have the intensity in any one spot to grow bud... In this case, the entire crop woukd suffer of low yield.

no it wouldn't. Use enough cobs to blanket the entire canopy evenly with the amount of light needed. Easier to do with multiple light sources. Total amount of light would be the same as a single light source.

the water hose analogy posted previously in this thread, explains better.

 

[churchhaze]

A bunch of weaker beams will OVERLAP. Intensity is higher in the area of OVERLAP.

I'm going to say I give up now, but I will never back down!!!

Photons are discrete packets of energy. They don't clump together to form penetrating cannon rounds just because they start off closer together. They're discrete packets whether they come from one powerful source or many weak sources...

Here's 2 circles overlapping. The dark gray area represents where the 2 circles OVERLAP. The gray is grayer in the area of overlap.

 

[Hybridway]

no your not interpreting it correctly.

-assume I have a single point light source that provides 1000 umoles.
-assume further that its set at a height to distribute its light over a 5x5 area with minimal wasted light going up or sideways, using the inverse square law to estimate height from the top of the canopy.

-assume that you haave 4 point sources of light that are 250 umoles each.
-assume that you spread out the four lights to cover the 5x5 area with minimal wasted light using the inverse square law and evenly overlap between the four different point sources.

The 4 point sources of light will penetrate deeper and provide more even coverage than a single large point source for the 5x5 area

What in saying is that in your example provided each of the 4 spread out light sources is 250 umol output or delivered. Whatever. Doesn't matter. As opposed to a center LES or whatever delivering 1000 umols to the plants.
With that scenario, there will never be a higher output then 250 depending on how far apart they are. Although spread evenly, it will never be enough to flower, but a single 1000 umol source would be.
If all 4 sources of light put out 600-1000 then you could grow bud better then a 2400-4000umol center output les.
So, you're right as long as each les (whatever you use) is providing enough output to flower.
Spreading out is deffinetly better but only as long as each source is intense enough to adequately flower.

 

[BOBBY_G]

I lied, the other thing you are missing is that PPFD is a spot reading.

It's like a garden hose man. You can make a narrow stream and blast it in the midddle of your lawn, and all you will do is kill the grass there. We want a wide, EVEN stream. That's what HID reflectors do, or multiple light sources, or lenses.

The inverse square law means less light for a given area, because light spreads, it doesn't disappear.

And has anybody bothered pointing out that the second you add a lens or reflector the inverse square law doesn't even fucking apply?

it kinda follows the same rule but the factor may be different.

lol beat me to it

WHOOP WHOOP

 

[Greengenes707]

1000µmols PPF is 1000µmols PPF no matter where it is coming from. Means you have a 1000µmols/second to work with. We can get down to YPF of each spectrum if we really want to. But the difference between an HID and white based LED is 2% in YPF of the entire spectrum, favoring LED's.
1000PPF is a photon count...takes ~8-10 photons to fixate a carbon molecule.



Raise your hands if you have put a PAR meter under a canopy??? And tell me how well the inverse square law was represented???

 

[OneHitDone]

1000µmols PPF is 1000µmols PPF no matter where it is coming from. Means you have a 1000µmols/second to work with. We can get down to YPF of each spectrum if we really want to. But the difference between an HID and white based LED is 2% in YPF of the entire spectrum, favoring LED's.
1000PPF is a photon count...takes ~8-10 photons to fixate a carbon molecule.

View attachment 3715198

Raise your hands if you have put a PAR meter under a canopy??? And tell me how well the inverse square law was represented???

Forgot 1 scenario

 

[JorgeGonzales]

1000µmols PPF is 1000µmols PPF no matter where it is coming from. Means you have a 1000µmols/second to work with. We can get down to YPF of each spectrum if we really want to. But the difference between an HID and white based LED is 2% in YPF of the entire spectrum, favoring LED's.
1000PPF is a photon count...takes ~8-10 photons to fixate a carbon molecule.

View attachment 3715198

Raise your hands if you have put a PAR meter under a canopy??? And tell me how well the inverse square law was represented???

You forgot the laser beam/death ray scenario. It involves setting plants on fire with ultimate penetration.

I don't understand the bizarre "intensity" and "penetration" memes around here at all. Those words don't mean what people think they mean. Hot spots are bad, yo.

 

[BOBBY_G]

::waits for jorge's "ultimate penetration" video::

 

[MrTwist1]

What in saying is that in your example provided each of the 4 spread out light sources is 250 umol output or delivered. Whatever. Doesn't matter. As opposed to a center LES or whatever delivering 1000 umols to the plants.
With that scenario, there will never be a higher output then 250 depending on how far apart they are. Although spread evenly, it will never be enough to flower, but a single 1000 umol source would be.
If all 4 sources of light put out 600-1000 then you could grow bud better then a 2400-4000umol center output les.
So, you're right as long as each les (whatever you use) is providing enough output to flower.
Spreading out is deffinetly better but only as long as each source is intense enough to adequately flower.

SO how do you explain the suncloak? Each of those diodes puts out a tiny amount of radiation, but cumulatively it is enough light to flower.

 

[Hybridway]

SO how do you explain the suncloak? Each of those diodes puts out a tiny amount of radiation, but cumulatively it is enough light to flower.

This is exactly why I know what I'm saying from experience.
Also, general rule of thumb when flowering with HPS is never use anything less then a 600 unless it's supplemental.
Any plant flowered should be to its fullest potential with what you have to work with.
Do not choose to not have enough if you don't have to. So, I will never buy any fixture as primary lighting that cannot cause a plant to be allowed its potential. Otherwise I'm only wasting space, plugs, soil, nutes, ect.....
4 , 600's will yield me just as much using 2400w as 3, 1000's using 3000watts. So, the spreading does work to your benifit in this case.
But spread out 250's or 400's & your plants simply cannot put out the bud they want to, need to, because the 250's & 400's simply do not put out enough intensity. Sure, you can put the fixtures right next to each other but what's the point of that?
There's so many promoting underlit spaces here whether it's a pre-made fixture or super-soft running COBs, everyone's getting confused. So much in fact that they'd rather save $4.00 a month on a fixture running cost then yield the extra 4 oz. and that really sucks for new led users trying to get a grip on this stuff.
Why buy or make any fixture that cannot do its job? Any led used IMO should be at least a 600watt HPS equivalent unless it's supplemental, side-lighting, or enhancing a spectrum. Why, because a 600watt HPS can yield a pound.

 

[dandyrandy]

All of this penetration talk, I'm taking the old lady to bed.