Bridgelux Gen2 BXEB-L0560Z-30E2000-C-B3 First Look

Thanks, mate!

That sounds good! As I said, I like looking for tools and have a lot links saved for speaker construction, light and a few others


Do you know this tool?
http://dev.edman007.com/~edman007/pub/par-dli-cal.html

Randomblame said:

I also like such tools, the more the better...!
Even if it does not include the reflections ... it is good for open space calculations. Any plans to make it accessible to all, as a web app maybe?

Click to expand...

What would you do with it though? Like I said, the rule of thumb for determining correct height I proposed long ago is all you need.

Besides it doesn't matter that much anyway. As long as people understand inverse square calculations are utterly useless with respect to fixture heights, it's clear that you lose or gain only a few percent with every inch you go up or down.

I wrote a simulator which does cover reflection and runs at a much higher resolution. Having that available, I personally don't see the need for running it anymore after verifying the rule of thumb. Let alone there is any need for something that only simulates the center of the light "sort of" correctly when you stay pretty close to the light.

GrowLightResearch said:

Pay no mind to the reflections. At LED heights and the directional nature of LEDs, the reflections are negligible. At high heights and with an isotropic light source then we can talk about reflections.

Click to expand...

The trouble is that you insisted on measuring at reflection in the middle of the tent close to the lights. That's just dumb. Then you were staggered to find that further away you got 30% more light. It's a bit daft for someone who just had his first encounter with what reflection does to pretend he knows the ins and outs.

Not adding reflection renders the simulation rather useless since the edges don't match reality.

In most grow tents at least half the grow is close enough to a wall to see big differences due to reflection. That's why all your simulated images have this yellow/green edge around them which should not be there.

It gets worse and worse the further you increase the height. You are basically modelling the light in an open room and you then cut out the fraction of the light footprint that falls withing the surface area of the tent. That's not even close to reality.

Led promoters do this on purpose. They pretend a Gavita 1000W produces only a tiny bit of light that way. What they really show is that only a third of the light falls within the grow tent's footprint when the light is a meter up. So yeah, when you measure only a third it looks bad.

In reality the light bounces back off the walls and the difference between led and HPS is much smaller than they try to lie.

If someone wrote a reflections calculator that worked, they deserve a Nobel Prize. It could not be done in a matter of hours if at all.

Click to expand...

Lol, because you have no clue how to calculate it, it must be impossible? Pffft.

Well I did it and I'd love to see that Nobel prize coming my way. But I doubt they give those away for something any self respecting programmer could whip out in a few hours.

wietefras said:

What would you do with it though? Like I said, the rule of thumb for determining correct height I proposed long ago is all you need.

Besides it doesn't matter that much anyway. As long as people understand inverse square calculations are utterly useless with respect to fixture heights, it's clear that you lose or gain only a few percent with every inch you go up or down.

I wrote a simulator which does cover reflection and runs at a much higher resolution. Having that available, I personally don't see the need for running it anymore after verifying the rule of thumb. Let alone there is any need for something that only simulates the center of the light "sort of" correctly when you stay pretty close to the light.

Click to expand...

As I said, I like tools and online calculators of all kinds. Whether they are useful to me, I decide if I tested them. As you said, and me too, this tool (with no reflections included) is suitable for open spaces and that's what I'll try.
Is your tool somehow available to others? Is there maybe a link? I like such tools!
I even have one that calculates the translation of my racing bike and helps me combine the right sprockets and cassettes, depending on the planned route.
What do you think about the tool that I posted above? Have you ever tried it?

BTW,
GLR gets so much headwind here, I find it remarkable that he is still here. And at least one must keep him happy, right? Not that he starts drinking or something even more worse...

Are you guys familiar with Dialux 4 or Dialux Evo ?
I've did some simulations too using this software to compare a CXB and F-Series setup at 4'x4'.

Very nice comparison.
Shows without words what advantages the use of strips brings.
Unfortunately, I do not use Windows anymore, so I can not say anything about the software.

Randomblame said:

GLR gets so much headwind here, I find it remarkable that he is still here.

Click to expand...

It's not so much remarkable as that it's disappointing he's still here.

He gets this "headwind" because he posts pretty much nothing but nonsense.

GrowLightResearch said:

For example a 1000W HPS is usually about 40" over the canopy. That's why it gets such good penetration.

Click to expand...

Of course that's why ...

He's shocked to find that reflection matters little in the middle of the tent and very close under the light. So he concludes reflection has no effect. This must be because leds emit special light not bothered by reflections ...

GrowLightResearch said:

Pay no mind to the reflections. At LED heights and the directional nature of LEDs, the reflections are negligible.

Click to expand...

He's even more shocked reflection actually works when you measure it at a height where it does show even in the middle of the tent:

GrowLightResearch said:

Mostof my recent research into reflectivity
...
If we could get 30% increase in real life that would be fantastic. That 30% motivated me to try and find out. 30% is huge but all I have seen so far in real life is dismal. I need to know more.

Click to expand...

This is the first time he realizes reflection has any effect and this was a few days ago. Also, he only noticed after nfhiggs pointed out his measurements showed this increase due to reflections while he himself saw zero effect. Worse still, after measuring the effect himself he still contests whether it's actually there or not.

For someone who has supposedly researched the matter for years, that's a bit odd. Sounds more like somebody who is just starting to try to come to terms with the subject.

More nonsense about led light's special nature and now reflectors:

GrowLightResearch said:

Reflectors do not work well with LEDs due to the directional nature of LEDs.
The photons that hit the wall have very low intensity. If you look at the LEDs spacial radiation pattern what hits the wall will be less than 40%.

Click to expand...

I'll agree that reflectors on COBs is generally a bad idea, but his explanation is ridiculous. This also has to do with reflection losses. Both on the reflector itself, but also on the walls because with reflectors the light needs to hang higher to get adequate uniformity and then you end up with more light on the walls instead of less.

He keeps insisting "ISL" (as he calls it) applies to the distance of the light

GrowLightResearch said:

The measured values matched calculated ISL.

No Sides 40" 97 µMoles
No Sides 36" 117 µMoles

Click to expand...

Of course from only two points (close to each other) you cannot see if a line is linear, exponential, polynomial or whatever. In this case he's claiming the two points on the right of the graph are part of an inverse square relation. Clearly the line is pretty much linear (although it would look slightly different if measured correctly):


More nonsense about ISL and again the supposedly special nature of led light

GrowLightResearch said:

ISL is for isotropic approximate point light sources.
LEDs light distribution does not radiate the same intensity in all angles as a light bulb does.
Therefore the calculations must take the angle of the light light source with respect to the sensor and the distance of the light light source to the sensor.

Click to expand...

These are obviously two completely unrelated topics. ISL works prefectly fine for leds, stars or whatever light source. As long as you are further away than five times the size as he also keepos harping on about. He copy pastes factoids all the time. He just doesn't understand them and then doesn't see they are connected.

He actually thinks he can reverse the effect of ISL to adjust measuring PPFD at different levels

GrowLightResearch said:

I measured the distance from LED to sensor.

I then use PPFD/watt and Inverse Square Law to make them "comparable" at any height. I chose to compare them at 1 meter.

Click to expand...

Of course you can't correct for measured height. ISL does not apply like that. Funny how recently he suddenly changed his position and now claims that he knew all along that ISL doesn't apply to the height of the fixture. So now he should understand how wrong he was on all of these claims, but he keeps maintaining he was right all along.


He claims you cannot use a lux meter to measure uniformity for light of similar color/SPD. He even claims you cannot convert lumen/lux values to PPF/PPFD values by using a conversion factor. Everybody should by an expensi ve PAR meter because it's the most important tool to have for growers as ISL is the important factor in grow lights. In reality a PAR metes is the last thing you need and ISL is completely irrelevant. What matters for grow lights is uniformity and reflection of the walls.

At some point he sort of did understand that you can perhaps convert from PPF/PPFD to lumen/lux, but still he is right because of ... yeah not sure why, but right he must always be:

GrowLightResearch said:

A PPFD calculation requires the distance the photons travel, the angle at which the photons were emitted from the LED, and the spacial distribution of radiation. The conversion factor must be stated with a specific distance.

Click to expand...

Of course PAR meters are really special in that they have a CMOS imaging chip inside which measures the angles. Oh wait, no that was a sun direction sensor so satellites can find their orientation to the sun (which he actually thought was a PAR meter with a cosine corrector).

Of course a lux meter and par meter are pretty much the exact same tech. Just that they are each tailored to measure a different spectrum.


He claims PPF and PPFD are completely unrelated when I said that average PPFD can be calculated by dividing PPF by the surface area which you are lighting up (minus reflection losses).

GrowLightResearch said:

Dividing PPF by area will get you nothing near PPFD.

PPF has no relationship to area. It is a measurement of non-directional total emitted power.
PPFD must be specified with a height or it is useless. This is why conversion factors without a height do not work.
You also need the spacial distribution of radiation to make the calculations. LEDs are not an isotropic light source.

Click to expand...

He really has no clue whatsoever and my condolences to anyone expecting something useful to come out of his "research".

wietefras said:

It's not so much remarkable as that it's disappointing he's still here.

He gets this "headwind" because he posts pretty much nothing but nonsense.

Of course that's why ...

He's shocked to find that reflection matters little in the middle of the tent and very close under the light. So he concludes reflection has no effect. This must be because leds emit special light not bothered by reflections ...


He's even more shocked reflection actually works when you measure it at a height where it does show even in the middle of the tent:

This is the first time he realizes reflection has any effect and this was a few days ago. Also, he only noticed after nfhiggs pointed out his measurements showed this increase due to reflections while he himself saw zero effect. Worse still, after measuring the effect himself he still contests whether it's actually there or not.

For someone who has supposedly researched the matter for years, that's a bit odd. Sounds more like somebody who is just starting to try to come to terms with the subject.

More nonsense about led light's special nature and now reflectors:
I'll agree that reflectors on COBs is generally a bad idea, but his explanation is ridiculous. This also has to do with reflection losses. Both on the reflector itself, but also on the walls because with reflectors the light needs to hang higher to get adequate uniformity and then you end up with more light on the walls instead of less.

He keeps insisting "ISL" (as he calls it) applies to the distance of the light
Of course from only two points (close to each other) you cannot see if a line is linear, exponential, polynomial or whatever. In this case he's claiming the two points on the right of the graph are part of an inverse square relation. Clearly the line is pretty much linear (although it would look slightly different if measured correctly):
View attachment 4083069

More nonsense about ISL and again the supposedly special nature of led light
These are obviously two completely unrelated topics. ISL works prefectly fine for leds, stars or whatever light source. As long as you are further away than five times the size as he also keepos harping on about. He copy pastes factoids all the time. He just doesn't understand them and then doesn't see they are connected.

He actually thinks he can reverse the effect of ISL to adjust measuring PPFD at different levels
Of course you can't correct for measured height. ISL does not apply like that. Funny how recently he suddenly changed his position and now claims that he knew all along that ISL doesn't apply to the height of the fixture. So now he should understand how wrong he was on all of these claims, but he keeps maintaining he was right all along.


He claims you cannot use a lux meter to measure uniformity for light of similar color/SPD. He even claims you cannot convert lumen/lux values to PPF/PPFD values by using a conversion factor. Everybody should by an expensi ve PAR meter because it's the most important tool to have for growers as ISL is the important factor in grow lights. In reality a PAR metes is the last thing you need and ISL is completely irrelevant. What matters for grow lights is uniformity and reflection of the walls.

At some point he sort of did understand that you can perhaps convert from PPF/PPFD to lumen/lux, but still he is right because of ... yeah not sure why, but right he must always be:
Of course PAR meters are really special in that they have a CMOS imaging chip inside which measures the angles. Oh wait, no that was a sun direction sensor so satellites can find their orientation to the sun (which he actually thought was a PAR meter with a cosine corrector).

Of course a lux meter and par meter are pretty much the exact same tech. Just that they are each tailored to measure a different spectrum.


He claims PPF and PPFD are completely unrelated when I said that average PPFD can be calculated by dividing PPF by the surface area which you are lighting up (minus reflection losses).


He really has no clue whatsoever and my condolences to anyone expecting something useful to come out of his "research".

Click to expand...

You are so right, mate! But without him we would miss your explanations/corrections on the subject and these are worth a lot for people who really try to understand it.
And by the way, it's also amusing...

wietefras said:

So he concludes reflection has no effect.

Click to expand...

You continuously misquote me. You are purposely being deceptive by leaving out the rest of what I said.

I concluded conclusively, reflection has zero effect on Inverse Square Law (ISL).
Contrary to @wietefras that said that ISL does not work in a grow tent because reflection cancels ISL.
I proved your common sense "reflections cancel ISL" to be false at any distance.

The measurements were made to show reflections did not adversely affect ISL. The measurements were made at a non-real life height. The height was chosen to maximize the amount of reflection based on the distance to the walls and the strength of the intensity at the angles between the LEDs and sensor. But NOT a real life scenario.

Reflection quanta was added at each distance where the reflection also reasonably followed ISL.

wietefras said:

Of course a lux meter and par meter are pretty much the exact same tech.

Click to expand...

You continuously misquote me, again.

I was comparing a lux meter to spectrometer. Spectrometers can use photodiodes, CMOS imaging sensor, or CCD.

Even the $47 Public Lab spectrometer uses a webcam's CCD,
https://publiclab.org/notes/abdul/10-13-2016/desktop-spectrometry-starter-kit-3-0-instructions

A sun direction sensor diagram was simplest diagram I could find to explain the concept. I never mentioned cosine correction until I corrected you when you said cosine filter when you meant cosine correction. I did not reply to your cosine correction tangent because I did not care to open another can of worms with you. Prior to your cosine correction rant I did not refer to cosine correction. You went off on that tangent by yourself.

Not once did you prove me wrong on any material matter. You just used your "common sense" to say I was wrong because there was, as you said, no citations to back your "common sense".

wietefras said:

At some point he sort of did understand that you can perhaps convert from PPF/PPFD to lumen/lux, but still he is right because of ... yeah not sure why, but right he must always be:

Click to expand...

The key phrase: "not sure why".

I still stand by this: "Dividing PPF by area will get you nothing near PPFD."

It is true you can approximate PPFD by dividing PPF by area. Except the area is not not the area below the fixture. The area is typically 12.566370614 m². And except it's the equation for an isotropic light (e.g. light bulb). Does not work for a light source with a directional radiation pattern (e.g. LED).

Why 12.566370614? That is the result of 4⋅π⋅r ².

Where r is the distance. Remember I said you need a distance. Unless you do not believe ISL is real.

So why a radius² for distance? Distance to the area is a radius because PPF is derived from integrating sphere measurements. The area of a sphere is 4⋅π⋅r ².

wietefras said:

"ISL" (as he calls it) applies to the distance of the light

Click to expand...

"As I call it"? You never heard of abbreviations?

And ABSOLUTELY a distance IS required with PPFD. Required for ISL.

wietefras said:

Also, he only noticed after nfhiggs pointed out his measurements showed this increase due to reflections

Click to expand...

You continuously misquote me, again, and again.

The topic context was ISL not reflections. nfhiggs did not "point this out" He asked why I did not consider the reflections significant. And that was explained.

wietefras said:

Of course you can't correct for measured height. ISL does not apply like that. Funny how recently he suddenly changed his position and now claims that he knew all along that ISL doesn't apply to the height of the fixture.

Click to expand...

This bullshit is getting to the level of ad nauseam.

You continuously misquote me, again, again, and again.


The August 16,2016 experiment you trashed is how this disagreement started. It was some time before that that I knew ISL did not work for fixtures, even one as small as 12". That experiment showed WHY it does not work. It also show how to calculate the PPFD of a fixture using ISL using the distance between the sensor and each LED.

I have from day one said you cannot measure a fixture due to the five times rule. Because each LED emits photons at a different intensity at each angle of emittance and the distance from each LED is at a different distance to the sensor. As the height of the fixture changes so does the distance to each and every LED. But the distance between each LED does not change by the same percentage. It is required to apply ISL to each LED and sum their PPFD. That is what I proved with the August 16, 2016 experiment.

I found ISL did not apply to the 12" strip measurements at a distance of 100mm to 400mm. I then calculated the ISL for 8 of the 16 LEDs spaced 0.7" apart summed and doubled the 8 calculations and the result matched the measured value within ≈ 1%.

What was funny about this how you complained I did not know what I was doing because I only calculated 8 LED rather than 16. You did not understand the other 8 LEDs would would produce identical results.

100mm height measured 440 calculated 440
400mm height measured 164 calculated 166




To the above you said I proved your point ISL does not work. You said I should have measured 110 if ISL worked, proving you correct. That is because you did not understand, and still do not understand, when each LED is measured or calculated, ISL works. But the measured value will be less (110 vs. 166) than if you used ONLY one calculation using the two heights.

$angle = rad2deg(atan( $offset/$height)); where offset is the distance between the LEDs. Height is the height of the fixture over the sensor. This calculates the angle from the LED to the sensor. It is needed in the next equation.

$distance= $height / cos(deg2rad($angle)) ; Distance is between LED and sensor.

$irradiance = pow($ref/$distance,2) * $intensity[$angle]; Intensity is from the spacial radiation pattern in the LED's datasheet. $ref is the height of the first calculation. pow(ref/distance,2) is the equation for ISL.

The radiation intensities used for the Bridelux LEDs.


The loop for each height.
$ref = 3.93
for($i = 1; $i < 7;$i++){
$height = $i * .7857142857 + $ref;


The loop for each of the 8 LEDs.
for($j = 0; $j < 8;$j++){
$offset = $j * .7;

The above equations are for only one strip along the x axis.
In the PAR plots I posted used these equations plus I had to calculate distances including the y axis for each strip. Significantly more complex.

There were 672 LEDs and 22 x 24 points plotted = 354,816 loop iterations at each height.

wietefras said:

Of course that's why ...

Click to expand...

First "reflectors" was an auto-correct typo. It should have been reflections.

A 1000W HPS has an PPFD of about 400 µMoles at a distance to the canopy. at the recommended height of 1 meter.

With an LED fixture at distance of 12" can easily produce a PPFD of 400 µMoles. Is that equivalent to an HPS 400 µMole?

wietefras said:

Those calculated values look like nothing you would expect from 6 strips.

Click to expand...

There you go again, putting words in my mouth. No they are what I expected. Why you expect something else probably has to do with your faulty "common sense".

I guess you forgot about the measurements I did with a CoB. A CoB does not violate the "5 times rule". And guess what? The measurements made outside in open air nearly matched the measurements made in the tent. ISL worked exactly as it should in both cases. Reflections did not cancel ISL as you say.

Again it was humorous when you said the tent measurements were lower than outside.

It was a cold December night outside. What would that do to the relative flux of an LED?.

You dismissed the fact that ISL was not canceled by reflections and tried anything to discredit my work. All you had was a 1% difference between outside and the tent. Respectable margin of error. YOU cried about the reflections and how the tent should have had higher measurements.

You are the Wizard, did you know why? I even mentioned it was Christmas time when I ran the experiment.
Simply must go - Baby, it's cold outside
The answer is no -
Ooh baby, it's cold outside


A wizard like the Wizard of Oz.

Randomblame said:

GLR gets so much headwind here, I find it remarkable that he is still here. And at least one must keep him happy, right? Not that he starts drinking or something even more worse...

Click to expand...

That's nice. Thank you.

Randomblame said:

But without him we would miss your explanations/corrections on the subject and these are worth a lot for people who really try to understand it

Click to expand...

Corrections? Ouch.

I know he has been on here longer than me and gained some respect for his wizardry.
I'm afraid that respect will be lessened as long as I hang in here. He has been very good manipulating others with is ad hominem replies and misquoting me. He is very good at deception. Wizards sometimes do that. Stand by as I pull back the curtain and revel the Wizard of Oz imitator.

I make mistakes. I'm old and I drink. And the ability to edit is a shorter amount of time than it takes me to get sober. There is not enough liquor in Costa Ric'er to get me to think reflections cancel ISL.

Champagne don't drive me crazy
Cocaine don't make me lazy
Ain't nobody's business but my own
Candy is dandy but liquor is quicker
I can drink all the liquor down in Costa Ric'er
Ain't nobody's business but my own

You can ride a great big pink Cadillac to church on Sunday
You can hang around the house with your old lady on Monday
Ain't nobody's business but your own
Man, I don't care what in the world that you do
As long as you do what you say you going to
Ain't nobody's business but your own

wietefras said:

He actually thinks he can reverse the effect of ISL to adjust measuring PPFD at different levels

Click to expand...

Here is why I normalized the PPFD to 1 meter. From those two CoBs I compared. I did that to verify I was in the right ballpark with my measurements. When comparing two CoBs with different wattage I have to normalize to the same height. That's why I could use the same 700mA driver for both CoBs even though they had different wattage.

Here is how to convert lumens to lux. Notice the normalization to 1 meter. Notice the area is NOT the area under the fixture.

Mr. Wizard, why did they not use 4⋅π⋅r ²?





Below is a link to an equation using 4⋅π⋅r ².
Notice a distance is required. Or an area? Why is that?

https://www.rapidtables.com/calc/light/lumen-to-lux-calculator.html

wietefras said:

The trouble is that you insisted on measuring at reflection in the middle of the tent close to the lights. That's just dumb.

Click to expand...

I know it was dumb. It was you asking about those heights.

Yes I made reflectance measurements at 5" 10". You asked about 4" , 8" and 16".
Reflectance was a negligible 3%.

Then I did 40" and 36" because ISL works fairly well at those distances and even though those hights would never be used in the real world, they were positioned for maximum reflectance from that fixture and the distance to the walls.
Again reflections had zero effect on ISL.

ISL works perfectly at every height when the light source is a CoB. You said the reflections should cancel ISL.
Again reflections had zero effect on ISL.

If the reflections are there at 36" and when I move to 40" how are reflections going to cancel ISL?
The reflections are still there and the reflections also followed ISL.
When you saw ISL did not work how the hell did you conceive the idea reflections canceled ISL?
Huh Mr Wizard?

tomate said:

Are you guys familiar with Dialux 4 or Dialux Evo ?

Click to expand...

In the first frames at low height, on the left hand image, what are those four pinkish circles in the center?

I like. Why did @wietefras like yours and not mine? Yours has the yellow and green he was complaining about. If he wrote one with reflecance in a few hours, he should be able to write this on an hour. Do you believe he can do this in a few hours? I'm calling bullshit. He says I'm clueless. I actually laughed out load when I type that. @wietefras not only doesn't know. He does not know he doesn't know.

wietefras said:

Lol, because you have no clue how to calculate it, it must be impossible? Pffft.

Well I did it and I'd love to see that Nobel prize coming my way. But I doubt they give those away for something any self respecting programmer could whip out in a few hours.

Click to expand...

Key phrase: SELF respecting programmer.


Show us your equations for reflectance. I'd give a metal to you just for that. I cannot help you to find a chest to pin it on.
I'm especially interested in the reflections in the corners.
CORNER REFLECTOR: https://en.wikipedia.org/wiki/Corner_reflector



This is good: "because you have no clue how to calculate it, it must be impossible?"

Photons are a particle. They just bounce off the walls at the same angle they hit. Correct? Angle of reflectance matches the incident angle? Correct?

Not exactly. That's a model created from experimental results. It's not the way photons actually work.

I think it's impossible? I said it would probably take more years than I have left on this planet to include reflections. Impossible for you? ABSOLUTELY!!!

Richard Feynman an American theoretical physicist known for his work in the path integral formulation of quantum mechanics, the theory of quantum electrodynamics, and the physics of the superfluidity of supercooled liquid helium, as well as in particle physics for which he proposed the parton model. For his contributions to the development of quantum electrodynamics, Feynman, jointly with Julian Schwinger and Shin'ichirō Tomonaga, received the Nobel Prize in Physics in 1965.

In his lecture on reflectance Richard Feynman said:


And he is referring to a simplified monochromatic light source.



You wrote a reflectance app in a few hours. Put it up! Nobel Prize time.

So how do photons reflect???

This is how Feynman says they do (the second image). The first image, I am sure, is how @wietefras views reflectance. Even using the classic model till I do not believe he could ever write a refectance app for a tent that actually worked





Okay wietefras he says you are a classic.
Just like the Wizard of Oz is a classic.



In his lecture (which is for non-technical general public) he uses an analogy of a teh hand on a stop watch. When the photon hits the detector the hand stops. The direction of the hand is the direction the photon is inclined to go.

He may not say, but the stopwatch I believe is the energy oscillations of the photon. Each wavelength, or more meaningful, frequency (inverse of wavelength), the oscillations are at different frequencies adding to the complexity. The oscillation frequency determines the amount of energy the photon carries.

_________________________________________________

Since there are 602,214,085,700,000,000,000 photons in a µMole, how many will hit the 4 corners of the tent? At how many different angles. At how many unique points? Sounds infinite. Overwhelming. But I'm clueless. What do I know?




https://en.wikipedia.org/wiki/Corner_reflector

Feynman also said:



So photons are a particle.
Do you realize they are a subatomic particles?
Do you realize they are massless energy?
Do they bounce off a reflective surface?
What makes a surface reflective? Because reflective surfaces are shinny like a mirror?
What happens when a photon collides with an electron?
What happens when a photon collides with another photon?
When photons are reflected, is there a higher probability they will collide with the non-reflected photons?
When the reflectance of a thin film sputtered with aluminum is measured do they use a beam or wave to measure?
How does the refractive index of mylar affect the reflection from a coated piece of mylar?
How deep does a photon penetrate the surface?
If the coating is spherical particles of aluminum is it still a specular reflection, or diffused?
How does the wavelength of a photon affect reflectance?
What is the wavelength?
Why does wavelength affect the energy level?

Is it impossible??? Me I go with the impossible is only impossible until the impossible has been done.
Dr. Feynnam does not agree. But he's no wizard. Can't wait for Mr Wizard aka Wietefras to post his Nobel prize winning app here. Or is wietefras just full of _it?

Richard Feynman QED Lecture 2, Reflection and Transmission

wietefras said:

He actually thinks he can reverse the effect of ISL to adjust measuring PPFD at different levels

Click to expand...

You continuously misquote me, again, again, again, and again.

No I can take two PPFD measurements with different characteristics and distances then normalize them at one distance. I use ISL to do the normalization. Not reverse ISL. WTF?

There's example how your mind is like a sieve. Then you fill in the parts that leaked out with pure bullshit.

At no time did I ever say I could reverse ISL in any manner.

I use it to normalize. Like in the above purple example of converting lumens to lux. Normalized at 1 meter.

Randomblame said:

Thanks, mate!

Click to expand...

You're welcome.

Did you understand where and when to use it?

When I asked this question: With an LED fixture at distance of 12" can easily produce a PPFD of 400 µMoles. Is that equivalent to an HPS 400 µMole hung at 1 meter?

And what about the Cree reference fixture? There fixture matched the HPS spectrum, the same PAR map, and irradiance level at the canopy (≈400 µmpl/m²/s). Which fixture is better, technically? Why? Two clear reasons.

I attached the entire reference fixture's PDF. Pages 15 and 16, says it all.
There is clearly a huge difference between the number of photons reaching the leaves between the Cree reference design and the Gavita 1000W HPS. Which?

wietefras said:

He claims you cannot use a lux meter to measure uniformity for light of similar color/SPD. He even claims you cannot convert lumen/lux values to PPF/PPFD values by using a conversion factor.

Click to expand...

Conversions are for lumen/PPF and lux /PPFD

You can use a conversion factor to convert within the same geometries.
Examples:
lux (illuminance) > watts (radiometric irradiance) > Photon Irradiance (µmpl/m²/s)> PPFD (µmpl/m²/s)
Radiant power > Luminous flux > Photon flux > PPF (µmol/s)

There is no conversion factor for PPFD that does not include the distance. And the conversion factor would have to be for a very specific light source. No generalities.

If I have the PPFD and the distance it was measured at, I can convert to watts or lux at any distance.

You sent me two links to conversion factors. Apogee and Lumiled/Sylvania.

But I'm clueless? Right? Prove me wrong Mr. Wizard.

If YOU understood this stuff, you would have known better than to say these fallacious things.

I learned a lot by converting Illuminance, Irradiance,and PPFD to one another.
All you need is Planck's constant, Avogadro's number, speed of light, and CIE standard observer (for luminous conversions).

http://www.growlightresearch.com/ppfd/lux.html
http://www.growlightresearch.com/ppfd/convert.html
http://www.growlightresearch.com/ppfd/calcISL.html

wietefras said:

It's not so much remarkable as that it's disappointing he's still here.

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Look what RolliTup sent me about the time you posted the above comment:

None of what you says corrects for any of the mistakes you made. It's just nonsense over and over.

That's probably your biggest problem too. You will never learn if you don't accept that you still need to learn. Stop lying to the people here and to yourself that you understand even the basics.

It's impossible to explain everything you misunderstand, but I'll respond to two of the biggest nonsensical point you keep trying to make.

GrowLightResearch said:

You continuously misquote me, again.

I was comparing a lux meter to spectrometer. Spectrometers can use photodiodes, CMOS imaging sensor, or CCD.

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No you weren't. You were as usual throwing in everything in the hope some of it would stick.

Also PAR meters.

GrowLightResearch said:

A PAR meter's sensor use multiple photodiodes with various wavelengths. So NO, lux and PAR meter's do NOT use the same sensor.

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Bullshit of course. There is only one PAR sensor which does (or did) that. None of them use a CCD or CMOS sensor.

Then you go on to try and to impress us with your "vast knowledge of "cosine sensors":

A sun direction sensor diagram was simplest diagram I could find to explain the concept. I never mentioned cosine correction until I never mentioned cosine correction until I corrected you when you said cosine filter when you meant cosine correction.

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So again, you demonstrate to really have a sieve for a memory. You were the one who came up with the idea of a "cosine sensor". Which is a complete bullshit term.

It was really not just an accident that you picked the wrong image. You simply have no clue how any of those things work. This is the bullshit story you came up with:

The cosine sensor has an aperture much smaller than the sensor. The sensor has many photodiodes. The lux sensor has one photodiode. When the light comes through the aperture at an angle the beam of light will not excite the center photodiode. The angle can be obtained from the cosine of the height (aperture to center photodiode) and the angle of the beam. The angle is calculated by using the acrtangent of the height and distance from the sensor's center to the photodiode that was excited by the light beam.

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That has to be the biggest load of crap you came up with. And that's some feat.

A spectrometer does not do any of the shit you pretend a "cosine sensor" does either.

It was just your backwards idea that a par meter or spectrometer would be able to detect "ISL" where a lux meter doesn't. You claimed a cosine sensor (or cosine corrector) would do that. When in fact it does the opposite and tries to take in light from a very wide angle.

OK, so we revisited the lux meter vs PAR meter debacle. Then lets do some more "ISL". Just your made up term "ISL" is already so pathetic that it makes me cringe every time, but it is very "you".

Your stance on "ISL" is rather fluid, but in this case you were claiming that "ISL" applies to the height of a fixture:

Again reflections had zero effect on ISL.

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First of all try to understand it's both reflection and overlap. Then understand that inverse square is only relevant for point sources. We send "a wall of light" onto the plants. As uniformly distributed as we can. That's as far away from a point source as you can get.

What I did was to put your measurements in a graph to illustrate what kind of line it actually produces. You claimed you saw an inverse square relation going from 36" to 40". So this is an inverse square relation according to you?:


That's just overlap on it's own already already negating the effect of inverse square law.

Just stop pretending already.

GrowLightResearch said:

Look what RolliTup sent me about the time you posted the above comment:

You have been awarded a trophy: Seriously Likeable!​

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ROFL that's cute. Even at something childish as that, your cognitive dissonance helps you hide reality from you. Reality is that you barely get any likes. I would estimate that very few people here have less likes than posts. Yet you lower the bar by a country mile. You have only one like for every three posts. That has to be one of the lowest ratios here.

Can you say Ad Hominum?

And still misquoting me.

wietefras said:

That's just overlap on it's own already already negating the effect of inverse square law.

Click to expand...

Nice graph. I do not remember the numbers at 36" & 40" Like 97 and 120? That would be exactly what an ISL calculator would compute. But 40" is less than 2x the fixture's max 30" dimension. A little short of the 5x rule.

Just plug the 36" and 40" PPFD numbers into an inverse square calculator.

wietefras said:

Bullshit of course. There is only one PAR sensor which does (or did) that

Click to expand...

Take a look at the AMS TCS3400 Color Light-to-Digital Converter. Very inexpensive 4 photodiode sensor RGB+clear. A PAR meter cannot use an ambient light sensor. A PAR meter must have some spectral data. RGB minimum.

I have a couple of their AS7262 sensors, one a USB port the other on a serial port. The AS7262 will blow away most PAR meters. It is nearly spectrometer quality for $5.00. I will be writing an app for it very soon.
6 visible channels: 450nm, 500nm, 550nm, 570nm, 600nm and 650nm, each with 40nm FWHM. Perfect for horticulture spectrometry.

I've covered all your deceptive comments previously, so I hope we are done.