(μmol/s)/(PPFD) with respect to Hang height

Randomblame · Jun 16, 2019

Forget the stupid screenshot, it was a shitty example. Ashes on my head, please.
I've not tried to explain something or show him a better way I've just tried to answer his initial question and give him a calculator tool where he just need to enter a few numbers and tap calculate. If you have something like that for strips and cobs you could share it with him. Even if you can calculate it easily using your formula it can be faster in some situations to just enter a few numbers. For UV most important wavelength are 285 and 365 and he is trying to build an LED light that includes UVB an A. A working calulator would be for sure helpful to figure out the usable hanging heights because there are a few different diodes that can be used. Your tool seems to do exactly what I've mentioned and for what he has asked for in his 1st post. So why not share it with him?

SSGrower · Jun 16, 2019

Randomblame said:
Forget the stupid screenshot, it was a shitty example. Ashes on my head, please.
I've not tried to explain something or show him a better way I've just tried to answer his initial question and give him a calculator tool where he just need to enter a few numbers and tap calculate. If you have something like that for strips and cobs you could share it with him. Even if you can calculate it easily using your formula it can be faster in some situations to just enter a few numbers. For UV most important wavelength are 285 and 365 and he is trying to build an LED light that includes UVB an A. A working calulator would be for sure helpful to figure out the usable hanging heights because there are a few different diodes that can be used. Your tool seems to do exactly what I've mentioned and for what he has asked for in his 1st post. So why not share it with him?

I too would find this tool interisting as to my knowledge nobody has any means of modeling light from different planes. I have 3 planes of light generation in my set up, they can be modeled individually but there is no means to combine them so far as I am aware.

Multiple planes of emission are critical when considering advantages to be had with vertical farming, small footprint, supplimented natural light gardening.

@wietefras glad you have this tool share it or make it for sale please.

Randomblame · Jun 16, 2019

SSGrower said:
I too would find this tool interisting as to my knowledge nobody has any means of modeling light from different planes. I have 3 planes of light generation in my set up, they can be modeled individually but there is no means to combine them so far as I am aware.

Multiple planes of emission are critical when considering advantages to be had with vertical farming, small footprint, supplimented natural light gardening.

@wietefras glad you have this tool share it or make it for sale please.

Yeah, for dialux you need those IES files and those files are created by expensive equipment. If we would have something we just need to enter shape and lumen-, μMol- or μW-output and it calculates what you get at different hanging heights such a tool would of course be useful even if it calculates without reflective walls.

SSGrower · Jun 16, 2019

Randomblame said:
Yeah, for dialux you need those IES files and those files are created by expensive equipment. If we would have something we just need to enter shape and lumen-, μMol- or μW-output and it calculates what you get at different hanging heights such a tool would of course be useful even if it calculates without reflective walls.

I feel like this could be done on a per chip, board or strip basis. Mark, welight i think did this with strips for the solskin modeling. For my light Id only need ies files for single cobs, but so far as I could tell with dialux it only allows for a single plane of emission. There are at least millions of calculations that would need to be made for approximating 22 simulated point sources that are infact the combination of 96 simulated 2 dimentional hemispherical bastardizations of reality (aka a cree cxb3590).

Y'all see this btw?
http://www.rollitup.org/t/steel-cage-death-match-no-holds-barred.989844/

Rocket Soul · Jun 16, 2019

Hey Chief

As far as the whole hanging height/ppfd relationship: you wont be able to get a good equation unless you incorporate size of LES and form factor; 1 qb at full and 2 qbs at half is going to give quite different numbers.

But if this is more about how many UV chips to use: does it reall have to be all that even?
Its about triggering receptors in the plant, not cannopy height, and id think the activated receptor would affect all, or most of the plant?

Grow for fun only · Jun 17, 2019

ChiefRunningPhist said:
Depends on the chip, drive current, and operating temp, but you're probably at 2.15μmol/J if it's LM301B at 800W and what I'm assuming is a 4x4, unless it's high effeciency binning LM301B, then you might be 2.4μmol/J at 800W.

The SPD doesn't look like its added any red which could further increase effeciency, though again depending on chip selection drive current and thermal mgmt.

The new hlg is blasting ~2.6μmol/J with added high effeciency reds to bump the total effeciency even higher than if they used only the high effeciency bin LM301B they run. So a knockoff is most likely not using high effeciency bin LM301B, and it's not using red which could have had the possibility of boosting its effeciency, but even then if it did include red, they'd most likely be less effecient than the white they were running which would pull the 2.2μmol/J down to maybe 2.1μmol/J.

Those are just guesstimates but you can for sure know that the 2.9μmol/J is bullshit. Probably 2.3μmol/J at best is my guess.

Its a nice distribution, and it will grow the plant well, it's just not hitting 2.9μmol/J.

Got it,buddy, awesome expatiation there，Yes I see the PPE=PPF/Watt, it will depend on the watt and also the height for hanging the light, there's also some other factors impact the data, i will do more researches about this. :razz:

I didn't know much about the data mean before, but i see many ppl talking about data on lights, then i started to care about this. i need to learn more from you great guys . :clap:

Grow for fun only · Jun 17, 2019

Randomblame said:
It's possible to create something that reach 2,9μMol/J but you would need a hell lot of diodes which makes the fixture much more expensive. Quantumboard v2 diodes run at ~175mA or so and reach 2,5 without deepreds. To get 2,8 you need to run them close to test current which is 65mA, maybe 80mA is enough. And you have to use the exact same top bins. Because HLG gets selected top bins its not easy to find them if not impossible.
The SPD curve looks pretty similar to the QB redspec and they have not added much deep-red. So in the best case they increase efficiency by the same 0,1 which would mean 2,9 total.
Thing is, can you trust the seller/manufacturer?
Do they really use more expensive top bins?
Which deep-red diodes do they use? SMD5630's in deep-red would not improve efficiency. It needs at least top bin Prolight or Samsung deep-reds, Cree XPE2 or Osram Square would be even better.
They should at least have an independent lab test and not just a par map and a few numbers. If its something you can find on alibaba I would not trust them. Even for a DIY'er such a light would cost +1000$ build from quality parts.

Haha not have idea to do a DIY light or Create new thing by myself,also have no time

currently use the mars version. But I was just a little curious about the the data on light now, since several years ago i hardly heard ppl talking this words like 'PPE,PPFD',etc, ppl at that time just care about if the light grows plants well, and that time led is new to ppl, but today here's more and more led companies,and ppl have more choices, ppl have more different demands on light- high par, high watt, high ppe... anyaway I do get some new things from you guys it's very useful. You guys are very professional and nice to explain to new ppl, much appreciated it. i will do more researches for chip names or brands to feed my brain from now. :grin:

ChiefRunningPhist · Jun 17, 2019

All good points guys thanks!

UVB is a pretty damaging WV, so I'm guessing uniformity will be important to avoid hot spots. I'm really not sure how much of the plant needs UV, maybe you're right @Rocket Soul, that it only needs a bit of it somewhere on the plant to have the effect we like? Maybe you could just irradiate stems so you weren't damaging trichs?

@wietefras you make some good points about simplifying the process and how lengthy of a process it would be to truly implement ISL over a multi point light source within a reflective tent.

@Randomblame you've always something of value to add, the SS that you guys posted is interesting to me despite the fact that you were only showing me to point out there was an interactive calculator that I may want to check out.

@Moflow You just a fucking champ! Haha

ChiefRunningPhist · Jun 17, 2019

I'm wondering if the edge intensity diminishes in proportion to the length its from the source. Right under the light is X distance, the corner of the throw is much further and much less intense when not using optics to increase photon density to the outer boundaries.

I might just have to use a square optic that distributes evenly. Then just use simple trig (tanθ = opposite / adjacent, where θ = half beam angle, adjacent is hang height, and (2)×opposite is throw width) to calculate beam angle and spacing. It means there would be an optimal hang height depending on how I designed, which may or may not be what I'm after. I like the un-optic-ed light emissions because the photons are flying in all directions instead of just one way. With an optic you can achieve canopy saturation very effeciently, but the angle of emmision is such that I doubt you'd get as much penetration as un-lensed.

Moflow · Jun 17, 2019

I had a hoke around and found these.
1st pic is maybe a snapshot of a calculator of nomorefucks2give. I don't think he was keen to show some stuff due to the stick he got.
I couldn't find @nomorefucks2gives calculators that were mentioned but you could always contact the University in Florida were he worked in the led department? .... maybe as a janitor/handyman ? Lol
He had some issues, hope he's better now.

oldbeancounter · Jun 21, 2019

Grow for fun only said:
Haha not have idea to do a DIY light or Create new thing by myself,also have no time currently use the mars version. But I was just a little curious about the the data on light now, since several years ago i hardly heard ppl talking this words like 'PPE,PPFD',etc, ppl at that time just care about if the light grows plants well, and that time led is new to ppl, but today here's more and more led companies,and ppl have more choices, ppl have more different demands on light- high par, high watt, high ppe... anyaway I do get some new things from you guys it's very useful. You guys are very professional and nice to explain to new ppl, much appreciated it. i will do more researches for chip names or brands to feed my brain from now.

Go away Mars troll!!!!!!!!!!!!!

wietefras · Jun 21, 2019

ChiefRunningPhist said:
I'm wondering if the edge intensity diminishes in proportion to the length its from the source. Right under the light is X distance, the corner of the throw is much further and much less intense when not using optics to increase photon density to the outer boundaries.

It doesn't really "diminish", but yes the light gets more spread out with greater distance.

Light does not disappear from distance, but it spreads out. Which doesn't matter since it's still there and it will overlap with the other UV leds.

You really need to stop thinking in terms of "inverse square" and start thinking in "light distribution".

And yes, simple calculations, but you need a lot of them. Besides once you calculated them it will have told you nothing really.

It means there would be an optimal hang height

Yes, take the distance between the (uniformly spread out) leds and multiply that by 2/3 for an optimal hanging height. Or if you accept somewhat more

ps not sure why I cannot place images inside the post. Attached is a 4 led 2x2 matrix at a height of half the led distance (as opposed to 2/3 before).

JSheeze · Jun 21, 2019

wietefras said:
It doesn't really "diminish", but yes the light gets more spread out with greater distance.

Light does not disappear from distance, but it spreads out. Which doesn't matter since it's still there and it will overlap with the other UV leds.

You really need to stop thinking in terms of "inverse square" and start thinking in "light distribution".

And yes, simple calculations, but you need a lot of them. Besides once you calculated them it will have told you nothing really.

Yes, take the distance between the (uniformly spread out) leds and multiply that by 2/3 for an optimal hanging height. Or if you accept somewhat more

ps not sure why I cannot place images inside the post. Attached is a 4 led 2x2 matrix at a height of half the led distance (as opposed to 2/3 before).

Lol no.

ISL defines light distribution.

Your 2/3 rule is b.s., Chief has it correctly using the trig, 2/3 will only work with 1 angle and chief was talking about optics, you have no clue what ratio to multiply to find optimal hang height because you have no clue what optic he is using.

I've read your rant on penetration when going at random and moflow and it's very telling to your actual comprehension. Quit trying to act as if you know, because its clear you don't. A higher hung light with same canopy ppfd as low hung light will have greater intensity sub canopy than a lower hung light. Period.

wietefras · Jun 22, 2019

JSheeze said:
ISL defines light distribution.

Well technically beam angle does. Still you can indeed calculate light distribution given the beam angle and height and number plus distribution of light points if you You can calculate Yes if you compile a couple of million of those calculations then yes.

Your 2/3 rule is b.s.

No it is not. My "ISL calculations" have produced the charts posted above and they correlate to actual measurements.

Either way, when people light up rooms and offices, do they calculate the ISL for each light bulb for every cm2 of the room/office? No they simply hang a certain amount of lumen per m2 to get the desired average light intensity. That's exactly how it works with grow lights too.

To get 800umol/s/m2 as an average intensity, you need to hang about 800umol/s of light per m2 (plus some extra to counter for wall losses).

I cannot help that you are unable to grasp this simple concept, but I can only hope others will be able to at some point. I know it takes a lot of effort, but I try to help as much as I can.

A higher hung light with same canopy ppfd as low hung light will have greater intensity sub canopy than a lower hung light. Period.

Of course it does. because you would have to start with a much brighter light to get the same average PPFD from a higher hung light (if you assume ISL applies). Of course a 32000umol light has more "penetration" than a 500umol/s light yes. How is that even relevant?

The odd thing is that it's super easy to measure that ISL does not apply. So how is this even a debate? Simply take measurements while increasing the distance by 2. Every time you double the distance, the light intensity should drop by 4. So if you go from 4" to 64" you should be left with only 1/32 of the original intensity.

You can also see the intensity drop off slightly exponentially when you are closer than the "2/3 height" to the light. Below that the intensity only drops off by wall losses. Which also indicates in a way where the optimal hanging height is.

JSheeze · Jun 24, 2019

wietefras said:
Well technically beam angle does. Still you can indeed calculate light distribution given the beam angle and height and number plus distribution of light points if you You can calculate Yes if you compile a couple of million of those calculations then yes.

Lol
Well I actually know and understand what the ISL is, and because it's obvious you don't, you probably shouldn't be trying to explain it to people that actually do get it.

wietefras said:
Either way, when people light up rooms and offices, do they calculate the ISL for each light bulb for every cm2 of the room/office? No they simply hang a certain amount of lumen per m2 to get the desired average light intensity. That's exactly how it works with grow lights too.

To get 800umol/s/m2 as an average intensity, you need to hang about 800umol/s of light per m2 (plus some extra to counter for wall losses).

No one is trying to count lumens, we've progressed past that. We've found that total lumen count is a worse metric than PPFD. If people only cared about total lumen count then they'd just use HID, but they've found that precise targeting of certain areas intended for light means that calculating via total lumens and dividing by area is not accurate or effecient. A focused strip light at 600W isn't going to produce the lumens that a 1000W HPS will, yet it can still have a higher PPFD than a 1000W HPS due to optics, hang height, fixture design, ect, (and exactly what they've been talking about). So your b.s. statement that it's just averaging total lumens per m2 is like.. Duh.. But we're trying to go a bit further, and if you were comprehending you'd understand and not be arguing.

wietefras said:
The odd thing is that it's super easy to measure that ISL does not apply. So how is this even a debate? Simply take measurements while increasing the distance by 2. Every time you double the distance, the light intensity should drop by 4. So if you go from 4" to 64" you should be left with only 1/32 of the original intensity.

Go back and look up what ISL is and what steradians are and what the difference in beam angle does to intensity over distance. You're not comprehending. ISL is always maintained. You're only thinking of an un-impeded spherical emmission.

wietefras said:
You can also see the intensity drop off slightly exponentially when you are closer than the "2/3 height" to the light. Below that the intensity only drops off by wall losses. Which also indicates in a way where the optimal hanging height is.

SOH, CAH, TOA, basic trig here... Your 2/3 rule only works for 1 angle, look up what tanθ, sinθ, and cosθ are equal to.

wietefras said:
Of course it does. because you would have to start with a much brighter light to get the same average PPFD from a higher hung light (if you assume ISL applies). Of course a 32000umol light has more "penetration" than a 500umol/s

No not true. You don't have to start with a higher μmol light. That's kind of the whole point of this thread. A 1000μmol/s light with optics or a reflector can be hung at 10ft and have better sub canopy PPFD than a 2000μmol/s light without optics hung at only 6ft. It has to do with the proportion of additional distance traveled from the light source to the actual total distance from the light source. Also, do you see how the beam angle (which is a component of the ISL) would effect the total μmol/s needed to begin with? It has less to do with total μmol/s, and more to do with the radiant intensity per steradian and if that is maintained then a comparison between 2 lights' sub canopy PPFDs is soley dependent on the proportion modeled by the additional distance traveled, to the total distance from the light. IE a smaller additional:total will have a smaller impact on intensity drop vs a larger additional:total.

You're wrapping up fact with b.s. and that's a toxic combo for a forum.

ChiefRunningPhist · Jun 24, 2019

JSheeze said:
Lol
Well I actually know and understand what the ISL is, and because it's obvious you don't, you probably shouldn't be trying to explain it to people that actually do get it.

No one is trying to count lumens, we've progressed past that. We've found that total lumen count is a worse metric than PPFD. If people only cared about total lumen count then they'd just use HID, but they've found that precise targeting of certain areas intended for light means that calculating via total lumens and dividing by area is not accurate or effecient. A focused strip light at 600W isn't going to produce the lumens that a 1000W HPS will, yet it can still have a higher PPFD than a 1000W HPS due to optics, hang height, fixture design, ect, (and exactly what they've been talking about). So your b.s. statement that it's just averaging total lumens per m2 is like.. Duh.. But we're trying to go a bit further, and if you were comprehending you'd understand and not be arguing.

Go back and look up what ISL is and what steradians are and what the difference in beam angle does to intensity over distance. You're not comprehending. ISL is always maintained. You're only thinking of an un-impeded spherical emmission.

SOH, CAH, TOA, basic trig here... Your 2/3 rule only works for 1 angle, look up what tanθ, sinθ, and cosθ are equal to.

No not true. You don't have to start with a higher μmol light. That's kind of the whole point of this thread. A 1000μmol/s light with optics or a reflector can be hung at 10ft and have better sub canopy PPFD than a 2000μmol/s light without optics hung at only 6ft. It has to do with the proportion of additional distance traveled from the light source to the actual total distance from the light source. Also, do you see how the beam angle (which is a component of the ISL) would effect the total μmol/s needed to begin with? It has less to do with total μmol/s, and more to do with the radiant intensity per steradian and if that is maintained then a comparison between 2 lights' sub canopy PPFDs is soley dependent on the proportion modeled by the additional distance traveled, to the total distance from the light. IE a smaller additional:total will have a smaller impact on intensity drop vs a larger additional:total.

You're wrapping up fact with b.s. and that's a toxic combo for a forum.

Lol SOH CAH TOA! That's a blast from the past! :bigjoint:

If accurate, I'm assuming his 2/3 rule works because most of the chips are radiated at 120°. If they were altered from this beam angle though, I also question just how significant a 2/3 ratio really would be.

A 600W strip light might be getting close to a 1000W HPS light in terms of light output, probably not quite, but I see what you're saying and I'd have to agree with pretty much most of it as that's how I'm comprehending as well. I'd second the part about radiant intensity and penetration.

wietefras said:
To get 800umol/s/m2 as an average intensity, you need to hang about 800umol/s of light per m2 (plus some extra to counter for wall losses).

This is pretty good I think. I'm trying to be a bit more precise, but generally speaking I'd agree with that generic sentiment. I'm more concerned with hot spots and even distribution though I'd agree that's the basic jyst.

PSUAGRO. · Jun 24, 2019

Sooooooo when are you coming out with your light chief? Blux eb gen 3 on the short list?

PSUAGRO. · Jun 24, 2019

Moflow said:
View attachment 4351256 View attachment 4351259 View attachment 4351275

I had a hoke around and found these.
1st pic is maybe a snapshot of a calculator of nomorefucks2give. I don't think he was keen to show some stuff due to the stick he got.
I couldn't find @nomorefucks2gives calculators that were mentioned but you could always contact the University in Florida were he worked in the led department? .... maybe as a janitor/handyman ? Lol
He had some issues, hope he's better now.

I'm pretty sure that's from a movie......the janitor thing.

Moflow · Jun 24, 2019

PSUAGRO. said:
I'm pretty sure that's from a movie......the janitor thing.

MV5BMTM2MjMwNzI0M15BMl5BanBnXkFtZTcwNjAzMjcyMQ@@._V1_UY1200_CR89,0,630,1200_AL_.jpg

Nice SPD.... lol

PSUAGRO. · Jun 24, 2019

Why can't it ever be a chef in these roles? Nope, they can't do calculus on a ivy league chalk board, janitor sure....only massive amounts of cocaine and fucking the wait staff is what they're good at.....

Lol, farmers are lovable characters though. Not the ones that poison the earth for double tonnage / acre.

I Got a little dizzy, that's enough.....time for cbd/wine, perfect combo

(μmol/s)/(PPFD) with respect to Hang height

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