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Fogdog

Well-Known Member
You found someone, and only one, that defined a term named "specific brightness". The term "specific brightness" is not found anywhere else. In the same definition it says "specific brightness", intensity, radiance, and surface brightness are all the same.

One guy does not make a "technical community". What is reliable is an international system of units with a governing body.



Nope, "specific brightness" was a typo. It does not exist except on that one single solitary site. Except for the people that want to set their video monitor to a specific brightness.

Further more you conveniently excluded how this began.



Your "citation" throws SneekyNinja under the bus. He says it's intensity and NOT brightness. Your citation says intensity and brightness are the same thing. Whereas reliable sources say brightness was (as in past tense) synonymous with Luminance (an SI derived quantity) rather than Luminous Intensity (an SI base quantity) or Radiant Intensity (an SI derived quantity ) not being defined as being the same.





@dabby duck, you missed part of it.

Then there is the Federal Standard 1037C that said:
brightness: An attribute of visual perception in which a source appears to emit a given amount of light.
Note 1: "Brightness" should be used only for nonquantitative references to physiological sensations and perceptions of light.
Note 2: "Brightness" was formerly used as a synonym for the photometric term "luminance" and (incorrectly) for the radiometric term "radiance."

https://www.its.bldrdoc.gov/fs-1037/dir-005/_0719.htm

From US Dept of Commerce, Bolder National Laboratory :
NTIA/ITS Video Quality Measurement Techniques
https://www.its.bldrdoc.gov/publications/download/TR-02-392.pdf page xii

Offset or level offset:
An additive factor applied by the hypothetical reference circuit (HRC) to all pixels of an individual image plane (e.g., luminance, chrominance).

Offset of the luminance signal is commonly known as brightness.
NTIA Report 02-392, Video Quality Measurement Techniques, June 2002
There is no other reference to Specific Brightness other than the one guy on the Internet you found. That you so matter of factly used as your reliable source you tried to pass off as peer reviewed. Peer review is a group of experts reviewing a research paper. Not people on the Internet looking at a glossary.
nonsense. Common use of the word brightness isn't the same as when used by a bunch of pimple faced nerd virgins who speak in jargon.

Plants don't care about human perception of brightness. Neither should a person who is trying to grow pot.

Totally predictable you would complain about the sites I cited. What they say is that there is no need to follow a standard made according to how people respond to light in situations that don't involve people. Doesn't matter if it isn't endorsed in the book you read.

I stepped outside yesterday and with cloud cover, the sunlight wasn't bright. On a cloudless day at high noon in July it is very bright outside. Fuck your definition.

My PAR meter reads in W/m^2 or PPFD. I'm not going to talk about Photosynthetic Photon Flux Density in a normal conversation. The sun is bright. When a greenhouse grower wants to use ppfd to balance lighting in a greenhouse, they might use PAR readings to do so. Yet it would be appropriate for them to say "that area isn't very bright" when talking to his help in the greenhouse if he's working with less educated hired help. Jargon is appropriate when talking with other technical professionals or perhaps the LED subforum or used by someone like you who read a book and is faking it.
 
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dabby duck

Well-Known Member
Your par meter is useless for anything other than establishing a baseline, and the reason why they can use lux meters to reach the same measurement.....hence why we dont have handheld goniometers.

And dli is more commonly used thanjust pure ppf....ppfd isnt really a meaurement....
 

Fogdog

Well-Known Member
Your par meter is useless for anything other than establishing a baseline, and the reason why they can use lux meters to reach the same measurement.....hence why we dont have handheld goniometers.

And dli is more commonly used thanjust pure ppf....ppfd isnt really a meaurement....
My point is, this is the politics forum and if I want to say the sun is bright I don't need to refer to a technical manual beforehand. I'm also saying that the general public will get lost if a person starts talking in jargon that they don't use or understand.

Regarding "ppfd is not a measurement", from wikipedia: DLI describes the sum of the per second PPFD measurements during a 24-hour period. If lighting is constant, as it should be in a grow room, the conversion from ppfd to dli is a simple transformation. This is where you guys get bogged down in details that really unimportant to the average grower. I suppose you are going to come back with a "yeah but". (yawn, take it to the LED section)

I don't own a par meter anyway. I grow outdoors and pay attention to other things. If I were setting up a grow room for the first time it might make more sense to me to use a meter that measures lighting in the way a plant will use it rather than how a human perceives it. Especially when switching from one light source to a different type. But you are right, a good PAR meter is much more expensive than a lux meter. A lux meter can be useful to set a baseline and check for degradation in lighting thereafter, all other factors being kept constant. That said, there is so much more than light source to optimize when growing indoors. Which is why I chose to grow outdoors.

I do own a really cheap lux meter and haven't even broken it out of the packaging fwiw. I bought it when I was considering setting up an indoor grow. I bought it specifically to monitor lighting over time as you suggest. Once I chose to grow outdoors, I simply don't need it. I focus on other things such as the soil, amendments, bugs and keeping critters out. Mostly I simply enjoy growing the plant. It seems some people forget about that.

Getting back to the original disagreement with Growbulbretard, I don't give a fuck what technical standards say about human perception of brightness. Nobody gives a fuck about that other than technical professionals who work in industries that design, develop and deploy lighting for humans. He's talking in jargon and should take it where people care.
 

dabby duck

Well-Known Member
My point is, this is the politics forum and if I want to say the sun is bright I don't need to refer to a technical manual beforehand. I'm also saying that the general public will get lost if a person starts talking in jargon that they don't use or understand.

Regarding "ppfd is not a measurement", from wikipedia: DLI describes the sum of the per second PPFD measurements during a 24-hour period. If lighting is constant, as it should be in a grow room, the conversion from ppfd to dli is a simple transformation. This is where you guys get bogged down in details that really unimportant to the average grower. I suppose you are going to come back with a "yeah but". (yawn, take it to the LED section)

I don't own a par meter anyway. I grow outdoors and pay attention to other things. If I were setting up a grow room for the first time it might make more sense to me to use a meter that measures lighting in the way a plant will use it rather than how a human perceives it. Especially when switching from one light source to a different type. But you are right, a good PAR meter is much more expensive than a lux meter. A lux meter can be useful to set a baseline and check for degradation in lighting thereafter, all other factors being kept constant. That said, there is so much more than light source to optimize when growing indoors. Which is why I chose to grow outdoors.

I do own a really cheap lux meter and haven't even broken it out of the packaging fwiw. I bought it when I was considering setting up an indoor grow. I bought it specifically to monitor lighting over time as you suggest. Once I chose to grow outdoors, I simply don't need it. I focus on other things such as the soil, amendments, bugs and keeping critters out. Mostly I simply enjoy growing the plant. It seems some people forget about that.

Getting back to the original disagreement with Growbulbretard, I don't give a fuck what technical standards say about human perception of brightness. Nobody gives a fuck about that other than technical professionals who work in industries that design, develop and deploy lighting for humans. He's talking in jargon and should take it where people care.
Ppfd is simply a conversion of ppf in a square meter...photosynthetic photon flux is meat....nuance can be fine tuned or degraded....you get to choose and no one else, free will, cyninicsm free.....
 

Fogdog

Well-Known Member
Ppfd is simply a conversion of ppf in a square meter...photosynthetic photon flux is meat....nuance can be fine tuned or degraded....you get to choose and no one else, free will, cyninicsm free.....
You don't get it. Your fascination with jargon does not translate to general conversation.

Basically I just said you are boring and not welcome at parties.
 

see4

Well-Known Member
Quick question though.

How the fuck did an argument about light spectrums and brightness come up in a politics forum under a thread topic completely unrelated.
 

Fogdog

Well-Known Member
Quick question though.

How the fuck did an argument about light spectrums and brightness come up in a politics forum under a thread topic completely unrelated.
Good question. It all started when growadickresearch showed up and in a needy, narcissistic fashion started bleating jargon. I and others should have just put it on ignore rather than taking the bait.

I learn slow.
 
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see4

Well-Known Member
So I'm reading over this thread, and I must say, I didn't realize there was such a stigma with LEDs.

I've grown several harvests with LEDs. And many with MH/HPS. I love them both for different reasons.

But honestly, LEDs are getting pretty good these days. My last harvest was with LEDs. I gave some nugs to a mutual friend who works at a dispensary. He wants me to get the bud certified so they can sell it. -- I'd say that LEDs are good enough for primetime if you can get "endorsements" like that.

The Dawg grows some dank nugs with just 4000k LEDs, and he shows it off in RIU. So to say the LEDs only produce fluffy garbage is pretty ignorant. I can personally attest that it does not. I mean, it can, but if you're a good grower, it can produce just as good bud, if not better.

Don't get me wrong though. 1000 watts of HPS dank is some good lovin. But you shouldn't completely rule out LED. Hashtag, motherfuckin sayin.
 

GrowLightResearch

Well-Known Member
I was with you on some of your points, but dude, this is just retarded. On all counts. Sorry man.
And that is why no one tries. The impossible is only impossible until someone does it.

With quantity seven 4' Strips @ 25 watts ≈ 5000 lumens (Bridgelux EB Gen2 or Samsung F-Series Gen 3) the ideal height for max uniformity is 4". 7 x 5000 = 35,000 lumens and 175 watts.

A 120,000 lumen 1000W HPS is typically hung 1 meter or about 40", over the canopy.

Despite the HPS is 120,000 360° isotropic lumens and the LEDs are directional with a 60° apex (120° view angle) the LEDs will produce more lux per lumen looking at the lumen top lux as equal the LED strips will equal a 1000W HPS at 21.6" (likely even if hung higher than 22" ).

About 1 month ago someone on Reddit, with an Apogee MQ-501, measured a PPFD at the center of 510 µmols/m²/s with Bridgelux BXEB-L1120Z strips at 20" using eight strips.
A Gavita 1000W HPS at 1 meter PPFD center measurement was 380 µmols/m²/s.

Using inverse square a 510 µmol at 21.6" would be 14,875 at 4" 21x an HPS. Conservatively reducing the 175W by 20x = less than 9 watts.

9 watts sounds insane. 60 watts is looking reasonable.

I purchased two 24" BXEB-L0560Z-30E2000-C-A3 to do some preliminary testing while the 48" BXEB-L1120Z-30E4000-C-B3 are on backorder.

So far, a 60 watt LED replacement for a 1000W HPS looks very doable.

Here is someone using the Bridgelux strips:

Start of week 8.
 

see4

Well-Known Member
And that is why no one tries. The impossible is only impossible until someone does it.

With quantity seven 4' Strips @ 25 watts ≈ 5000 lumens (Bridgelux EB Gen2 or Samsung F-Series Gen 3) the ideal height for max uniformity is 4". 7 x 5000 = 35,000 lumens and 175 watts.

A 120,000 lumen 1000W HPS is typically hung 1 meter or about 40", over the canopy.

Despite the HPS is 120,000 360° isotropic lumens and the LEDs are directional with a 60° apex (120° view angle) the LEDs will produce more lux per lumen looking at the lumen top lux as equal the LED strips will equal a 1000W HPS at 21.6" (likely even if hung higher than 22" ).

About 1 month ago someone on Reddit, with an Apogee MQ-501, measured a PPFD at the center of 510 µmols/m²/s with Bridgelux BXEB-L1120Z strips at 20" using eight strips.
A Gavita 1000W HPS at 1 meter PPFD center measurement was 380 µmols/m²/s.

Using inverse square a 510 µmol at 21.6" would be 14,875 at 4" 21x an HPS. Conservatively reducing the 175W by 20x = less than 9 watts.

9 watts sounds insane. 60 watts is looking reasonable.

I purchased two 24" BXEB-L0560Z-30E2000-C-A3 to do some preliminary testing while the 48" BXEB-L1120Z-30E4000-C-B3 are on backorder.

So far, a 60 watt LED replacement for a 1000W HPS looks very doable.

Here is someone using the Bridgelux strips:
Are you an advertiser?
 

GrowLightResearch

Well-Known Member
Claiming that a 60 watt LED will replace a 1000 watt HPS bulb, sounds like advertiser bullshit to me.
I'm claiming there is a very good possibility that 1,008 LEDs spread uniformly across the canopy at a height of 100mm will beat the shit out of an HPS at 1 meter.

I showed you the math. It's about the uniformity of the irradiance (e.g. PPFD), spreading the photons proportionately across the canopy. The greater the uniformity the less the distance required between fixture and canopy. The difference in irradiance between a height of 1 meter vs. 100mm is 100x. For 1% of the electrical power you get the same amount of radiant power reaching the leaves. These 1200mm strips sell between $10 and $15. There is no way a small volume manufacturer could compete with those prices and distribution network. Samsung has the ability to bin their LEDs by forward voltage to a very tight tolerance which allows them to wire the LEDs in parallel and maintain a reasonable current balance and thereby uniformity. Using many mid power LEDs spread out keeps the temperature down to around 40° C. This minimizes thermal issues and maximizes efficacy.
 

SneekyNinja

Well-Known Member
I'm claiming there is a very good possibility that 1,008 LEDs spread uniformly across the canopy at a height of 100mm will beat the shit out of an HPS at 1 meter.

I showed you the math. It's about the uniformity of the irradiance (e.g. PPFD), spreading the photons proportionately across the canopy. The greater the uniformity the less the distance required between fixture and canopy. The difference in irradiance between a height of 1 meter vs. 100mm is 100x. For 1% of the electrical power you get the same amount of radiant power reaching the leaves. These 1200mm strips sell between $10 and $15. There is no way a small volume manufacturer could compete with those prices and distribution network. Samsung has the ability to bin their LEDs by forward voltage to a very tight tolerance which allows them to wire the LEDs in parallel and maintain a reasonable current balance and thereby uniformity. Using many mid power LEDs spread out keeps the temperature down to around 40° C. This minimizes thermal issues and maximizes efficacy.
I see you're STILL missing the point about intensity...

You cannot apply the inverse square law to multiple dispersed light sources as though they were one single source.

And in parallel why would the forward voltage matter at all?

You're a shit talker, friend.
 
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