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Let their be light! An open discussion about the science of light.


shaggy

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Just found a new term to research...lol
These manufacturers seem to try to confuse the consumer.

  • Photobiological Photon Flux Density (PBFD): 280 - 800 nm
    My guess is this is a term for a term already in use....PUR which is Photo Usable Radiation.

That is just what the plant is able to absorb.
They still try to confuse me, but it just makes me want to know more.
I love to help sponge brain people......all the knowledge in the world still die with you.

I guess you could write a book or become famous, but I am a terrible business man.
I love free shit, so I just give everything away.....you know be the friend you would like to befriend sorta shit I guess.
Nobody breaks the shit down for us street rats from Detroit or wherever you are from.
It has been a hard task translating science into stoner language.
Most stoners are quite intelligent, they are thought of a dumb and slow thinkers.

But in reality they are really just looking deeper into things than your average joe.

And therefore you may get a slow response to a question, rather than just spouting off at the mouth....🤓

Let see what google says of this new term...LOL

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Photosynthetic Photon Flux Density (PPFD) is the metric used to measure PAR over a square meter. It is a total count of light energy (in photons) from 400nm to 700nm that reaches a particular point on a plane. 

 

Photobiological Photon Flux Density (PBFD) is the metric used to measure PBAR over a square meter. It is a total count of light energy (in photons) from 350nm to 800nm (or the PBAR range used) that reaches a particular point on a plane. 

PPFD and PBFD are both expressed as μmol/m2-sec. See how PPFD and PBFD are measured below.

PPFD-PBFD-equation.png

Measuring PPFD and PBFD

PPFD and PBFD are measured using a light meter. A light fixture will be placed a distance above a plane and measurements will be taken at points within a specified coverage area.

The output of light from a fixture will vary based on the position of the light meter. For example, a light meter placed directly underneath the center of a fixture may reveal a higher PPFD/PBFD number than when placed in the corner of a 4ft x 4ft square. This is due to the reflector and the properties of its design.

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Ok, now what the fuck is PBAR?
Photobiologically Active Radiation (PBAR) is a range of light energy beyond and including PAR. Defining the specific range for PBAR is difficult as there are discrepancies of which nanometers the range should include. Some use 300-800nm while others use 350-800nm or 280-800nm.

 

photonchart-PBAR.png

Note the last line on the photo...
Total Photons Available for
Sounds a lot like PUR to me........What say you folks????
This shit will make your head spin, as I said before I believe it is by intention.

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So to sum things up quickly here.....

 

PAR = Photo Active Radiation

This is simply what is available in the present light spectrum.


PUR = Photo Useable Radiation.
This is simply what a plant can use in the present light spectrum.

 

What is non-useable light you may ask.....


X-rays may be present as well as UVC, but to my knowledge they are not useable by the plant.
In fact they are extremely harmful at certain levels, but I wonder if anyone has studied micro dosing.
I believe even micro-doses of x-rays can mutate genetics.
I have heard tell of x-rays used to mutate seed genetics, but no real experience with it myself so hearsay at this point.

UVC kills micro organisms, so I would assume eventual cell death also.

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On 1/12/2022 at 10:01 PM, crownpoodle said:

It gives me stuff to do when I'm on nocturnal mode.

I stay in nocturnal mode. If my plants are awake so am I.

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On 1/12/2022 at 10:59 PM, shaggy said:

So to sum things up quickly here.....

 

PAR = Photo Active Radiation

This is simply what is available in the present light spectrum.


PUR = Photo Useable Radiation.
This is simply what a plant can use in the present light spectrum.

 

What is non-useable light you may ask.....


X-rays may be present as well as UVC, but to my knowledge they are not useable by the plant.
In fact they are extremely harmful at certain levels, but I wonder if anyone has studied micro dosing.
I believe even micro-doses of x-rays can mutate genetics.
I have heard tell of x-rays used to mutate seed genetics, but no real experience with it myself so hearsay at this point.

UVC kills micro organisms, so I would assume eventual cell death also.

Good to know. That makes sense. 

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Just now, Jace said:

Good to know. That makes sense. 

I have considered adding uv bars to the room. I have read that some types of UV increases quality. Don't know much about the subject.

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