Blue brother
Well-Known Member
I can say abit more on it if you’d like?
HPS vs. LED Grow Lights — Which is Better for Growing Weed?
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Rocket Soul
Well-Known Member
Please....
First you might wanna define intensity. In SI units if you can. What is it? What is this intensity you quote, can you actually explain it? Intensity, as defined by lumens and lux is how bright something is to the human eye. Its a human centric measure based on our eyes.
Photosynthesis - Wikipedia
en.m.wikipedia.org
Now have a look at photosynthesis, look for where it talks about co2+ h20 + light = sugars and o2. Does it say "intensities" or "photons" ? Photosynthesis is photon dependant, not intensity dependant. Its a fact you can look up. It takes, at best, 48 photons, to make a molecule of sugar for the plant. No amount of intensities can make photosynthesis happen, intensity is something which happens around those photons but only in our eyes. Of course, the 48 photons will have some "intensity" in our eyes but this will vary wildly with the nanometers of the light: one photons worth of green light is much more bright and intense than one red one.
Ive added this for anyone too lazy to look it up:
Rocket Soul
Well-Known Member
Pleaee do but first have a look at the link i posted, have a look into photosynthesis, read up on lumens and lux, and then lets talk.
Blue brother
Well-Known Member
Yes I concede. When we talk about intensity as our perception of how many photons hit given surface in a certain amount of time then that is correct and yes we can add this up and we do measure for his in lux (how many photons we can perceive hit our eyes) What I am referring to is the intensity of the wave. The unit is watts/steradian. Energy flux is determined By the output and also the ability of light to move through something, in our case air or leaves. The intensity of the wave is directionally proportionate to the square of its amplitude (sure I’ve got that right… haha it’s been a while). So unless we change the amplitude, we cannot change the intensity. Yes different frequency waves carry more or less energy at the same amplitude but not more intensity. When we add another identical source all we are doing is adding more waves, not changing the amplitude or intensity of the wave.Please....
First you might wanna define intensity. In SI units if you can. What is it? What is this intensity you quote, can you actually explain it? Intensity, as defined by lumens and lux is how bright something is to the human eye. Its a human centric measure based on our eyes.
Photosynthesis - Wikipedia
Now have a look at photosynthesis, look for where it talks about co2+ h20 + light = sugars and o2. Does it say "intensities" or "photons" ? Photosynthesis is photon dependant, not intensity dependant. Its a fact you can look up. It takes, at best, 48 photons, to make a molecule of sugar for the plant. No amount of intensities can make photosynthesis happen, intensity is something which happens around those photons but only in our eyes. Of course, the 48 photons will have some "intensity" in our eyes but this will vary wildly with the nanometers of the light: one photons worth of green light is much more bright and intense than one red one.
Ive added this for anyone too lazy to look it up:
View attachment 5143871
When we look at luminous intensity all we are doing is counting the number of photons/space/time and forgetting about the wave. We must concerntrate on the wave if we want to determine the power of the light which directly correlates with the distance it can travel or depth it can penetrate.
although I am an optical engineer by trade this was a very long time ago so someone may be able to point out a mistake I’ve made, but I’m pretty sure what I’ve said is solid.
imagine 4 400ppf sources hung 1m above a canopy vs 1 1600ppf source, the amount of photons that hit the be canopy will be very similar resulting in similar luminous intensity (photons/space/time as we perceive) but the stream of photons is not more intense, just the way we perceive them hitting the surface is. There is no way the 4 250s have the intensity to penetrate or “shine” as deep or as “far” respectively as the 1000.
EDIT: I’ve edited this like 4 times since I posted it haha, I am rusty.
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Blue brother
Well-Known Member
There is some contusion here in optics because intensity can be used to describe irradiance, radiant intensity and also luminous intensity. The word intensity is also used as a term by other physicists to describe heat transfer
I wrote some answers to you guys, addresing some of the things you mentioned, but im too stoned to complete it right now lol
Blue Brother, your opinions and insights are amazing, much info on the topic at hand.
Hope i get to address some of the issues you brought up so we can share thoughts.
GN
Blue Brother, your opinions and insights are amazing, much info on the topic at hand.
Hope i get to address some of the issues you brought up so we can share thoughts.
GN
Just to simplify things, when you have multiple light sources that put short wavelengths, you will have the initial numbers, but just at a certain height and depth, because they are "short", they get to a certain distance and they dissipate or absorbed by the closest branches and leaves
(aka the canopy)
This is in straight relation to the amplitude (voltage) because when u have 1 light source that gives x wavelengths at y lengths, putting more of those wont change the length of the waves, just the qty of them at places that you put them in (spread)
So to conclude this, when you add voltage or intensity for our manner (unless they make 1w diode that gives 300 diodes power), you make stronger and longer waves, resulting in better ppfd which is just legnth of waves and how much they flux at a given surface and how much can be absorbed and if they encounter a canopy that absorb it, do they keep going deeper (long wave high voltage) or breaking and dissipating (short wave low voltage).
Blue brother
Well-Known Member
Fair play, to the best of my knowledge, what you’ve just said is correct. I was attempting to say the same thing but talked myself round in circles in my post lol.
PJ Diaz
Well-Known Member
What you are attempting to refer to is called Inverse Square Law, but it has nothing to do with short vs long wavelenghts, as wavelength has more to do with quality of light, not intensity.
Inverse Square Law - an overview | ScienceDirect Topics
xtsho
Well-Known Member
Top shelf cannabis can be grown under both HID and LED. Light is one of the most important factors but many suffer from a lack of other factors so regardless of light hey are disappointed at harvest.
HID's are much easier to grow with and a novice and first time grower may get better results using them. LEDs have a more complex learning curve to get really proficient with and that leads to many newer growers having issues that can be contributed to the lights.
With HID's it pretty much as simple as the back of the hand test to know where to put the lights and crank them up. With LEDs there are more factors at play with regard to light height, intensity, temperature, humidity, etc...
If you know what you're doing either light technologies will yield excellent results. One just uses less resources to achieve that goal.
HID's are much easier to grow with and a novice and first time grower may get better results using them. LEDs have a more complex learning curve to get really proficient with and that leads to many newer growers having issues that can be contributed to the lights.
With HID's it pretty much as simple as the back of the hand test to know where to put the lights and crank them up. With LEDs there are more factors at play with regard to light height, intensity, temperature, humidity, etc...
If you know what you're doing either light technologies will yield excellent results. One just uses less resources to achieve that goal.
Horselover fat
Well-Known Member
I don't think led is more difficult than hps. I think many growers got used to hps and adapting is difficult. A new grower just learns to grow with led. That said, I found the transfer easy. I went from 600w hps to 315cmh, then one grow using 200w of cobs and then to my 320w boards. The boards are best yet for me and my application. Both for quantity and quality.
Kassiopeija
Well-Known Member
You need to forget about this "light is a wave" for a moment because it's not relevant as photosynthesis is quantum-driven (@Rocket Soul is spot on!). To correctly measure light intensity for our purposes we use PPFD or PPF or YPF but lux/lumen is irrelevant and grossly misleading. Any surplus energy of a photon <680nm or <700nm is dispersed as (mostly) heat.
A photon is the gauge-boson of the electro-magnetic force that is timeless, has always the impulse of c, and either -1 or +1 spin meaning there can be an infinite amount of photons at any given point in timespace, though if a critical energy-density is overstepped then they will recombine into an electron-positron pair which swiftly mutually annihiliates one another (they spin in opposite directions but meet after half), sending 2 photons away into diametral directions. This is actually what happens right in the center of the sun and the reason, since this process is slow, why the light from its core takes many many years to reach the sun's surface, and briefly after, us.
Any usage of lumen or lux or else is really only misleading, though the radiant flux of a fixture can give another hint at the quality of the lightsource together with its PPF. As blue light or UVA uses more energy up to be generated and is crucially needed for both photochemistry or bud quality. Some modern LED fixtures claim +3.5umols but are mostly 660nm mostly designed for greenhouse amendment light where there is already sufficient of blue and green from the sun. The same fixtures (e.g. that watercooled which got mentioned previously) then show 2.8umols/J in its whitelight-configuration.
I'm not really sure if that's Snakedope's LED light is true to its claim of 2.8umols, it looks like a faildesign with closed (from above) heatsinks and black colour so as to encapture light and release back as IR. BUT, if 2.8umols/W is true then he is actually blasting his plants with more than double the photon-count as previously released by his HPS (1.5umols/W) - HPS-900PPF vs LED-2184PPF LMAO all the while making matters worse by trying to reduce warmth which will only further reduce enzymatic activity and just slow photosynthesis down, potentially leading to higher buildup of dangerous triplett excitation states inside the light-harvesting complexes causing singulett oxygen which can damage DNA, proteins essentially bleaching leaves from the inside out. That needs to be repaired plus there will be a much higher loss of carbon from respiration. You need to buy yourself a quantum meter and measure PPFD at canopy level, then use an IR gun to take leaf surface temps then adjust your environment to align with a proper VPD & DLI. There's charts. And not be so ignorant, deflective when others ask you rhetorical questions with the intent to point you into the right direction and forget about all your self-styled wisdom derived from druged logic theory. That's not science, just do a clean slate and discard all that into the trashcan.
About photons, "how far it can reach" - well, infinitely. It will never stop flying which is the reason why we can observe extremely distant objects like quasars/blazars or the cosmic background radiation which is old as about 300.000years after the Big Bang - so 13.7billion years. They fly, fly, fly just the electromagnetic field gets less dense with distance, except for when a laser is being emitted.
One of the reasons why this quanta-wave-duality is in existance is due to the Uncertainty Principle that means we cannot absolutely true pinpoint the location AND time of a quantum particle, its either we either miss the time or the location slightly and that is due to the inane error imposed by our methods of observation (we use quantum particles like electrons but mostly photons), which additionally influence the nature of what we want to observe experimentally. The most famous experiment to show this is the Doppelspalt-experiment but still, we can quantify the number of particles in or out, in a discrete fashion, giving a true number and also recombine its energy equivalency to a 100% true number. There's nothing mysterious about it it's just 2 sides of the same coin.
A photon is the gauge-boson of the electro-magnetic force that is timeless, has always the impulse of c, and either -1 or +1 spin meaning there can be an infinite amount of photons at any given point in timespace, though if a critical energy-density is overstepped then they will recombine into an electron-positron pair which swiftly mutually annihiliates one another (they spin in opposite directions but meet after half), sending 2 photons away into diametral directions. This is actually what happens right in the center of the sun and the reason, since this process is slow, why the light from its core takes many many years to reach the sun's surface, and briefly after, us.
Any usage of lumen or lux or else is really only misleading, though the radiant flux of a fixture can give another hint at the quality of the lightsource together with its PPF. As blue light or UVA uses more energy up to be generated and is crucially needed for both photochemistry or bud quality. Some modern LED fixtures claim +3.5umols but are mostly 660nm mostly designed for greenhouse amendment light where there is already sufficient of blue and green from the sun. The same fixtures (e.g. that watercooled which got mentioned previously) then show 2.8umols/J in its whitelight-configuration.
I'm not really sure if that's Snakedope's LED light is true to its claim of 2.8umols, it looks like a faildesign with closed (from above) heatsinks and black colour so as to encapture light and release back as IR. BUT, if 2.8umols/W is true then he is actually blasting his plants with more than double the photon-count as previously released by his HPS (1.5umols/W) - HPS-900PPF vs LED-2184PPF LMAO all the while making matters worse by trying to reduce warmth which will only further reduce enzymatic activity and just slow photosynthesis down, potentially leading to higher buildup of dangerous triplett excitation states inside the light-harvesting complexes causing singulett oxygen which can damage DNA, proteins essentially bleaching leaves from the inside out. That needs to be repaired plus there will be a much higher loss of carbon from respiration. You need to buy yourself a quantum meter and measure PPFD at canopy level, then use an IR gun to take leaf surface temps then adjust your environment to align with a proper VPD & DLI. There's charts. And not be so ignorant, deflective when others ask you rhetorical questions with the intent to point you into the right direction and forget about all your self-styled wisdom derived from druged logic theory. That's not science, just do a clean slate and discard all that into the trashcan.
About photons, "how far it can reach" - well, infinitely. It will never stop flying which is the reason why we can observe extremely distant objects like quasars/blazars or the cosmic background radiation which is old as about 300.000years after the Big Bang - so 13.7billion years. They fly, fly, fly just the electromagnetic field gets less dense with distance, except for when a laser is being emitted.
One of the reasons why this quanta-wave-duality is in existance is due to the Uncertainty Principle that means we cannot absolutely true pinpoint the location AND time of a quantum particle, its either we either miss the time or the location slightly and that is due to the inane error imposed by our methods of observation (we use quantum particles like electrons but mostly photons), which additionally influence the nature of what we want to observe experimentally. The most famous experiment to show this is the Doppelspalt-experiment but still, we can quantify the number of particles in or out, in a discrete fashion, giving a true number and also recombine its energy equivalency to a 100% true number. There's nothing mysterious about it it's just 2 sides of the same coin.
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Kassiopeija
Well-Known Member
The only exception to a quanta or single-photon-based evaluation is within the farred-region and everything that is considered under the phenomenum "Emerson-effect" where a photon >700nm is dependant on the presence of white light (driving photosystem 1) and uses phononic energy (locale heat) to drive photosystem 2:
(I have no data for Cannabis but it should, at least, be inclusive up to 750nm)
This also means that heat can be converted into biomass (energy is energy remember Einstein's equivalence) so this is where "the science on paper" falls short and gives less credence to HID lamps.
Actually Bugbee is now fighting hard to include this old and seemingly forgotten knowledge into a new supervised PAR range definition but is met by lots of autorative resistance. But the proof, which Bugbee showed in a series of various and highly developed experiments/studies, is there, there's really no way around it. It would be good if that happened to create a more even comparison ground for lamp fixture efficacy.
To further add:
A 250w HPS has a fixture efficacy of only 1.2umol/J and this, is much worse as a 1000w DE with 1700umols and a much greater life-expectationcy as a SE low wattage. Add in the higher hardware costs, will give you way less a bang-for-the-buck, even better light usage can be mitigate with enough minimum height of the 1000w HPS.
Also, there have been some recent tests done by MIGRO regarding PPFD prints and reflective walls and one thing is for certain, a growtent has very little lightloss so fixture height doesn't matter alltomuch. There is a huge error-in-thinking or measuring because many walls will disperse deflected light in a diffuse fashion but quantum meter sensors are designed to pick up a light-stream from a direction, ie. their sensor doesn't encapture true like a sphere from all directions so alot of diffuse light isn't weighted properly - it doesn't even make it inside the sensor! That is why we got Ulbricht integration spheres. Think of it this way: a lamp or fixture creates a discrete, specific amount of photons every second and these will 95% land upon your leaves IF you are in a tent that has highly reflective walls and the footprint is filled densely by leaves which are very efficient to collect photons.
^^ even that is with sensor error ^^
yes quality of wavelengths types, or spectrum in other words, is important as each type of wave has its own character and usesWhat you are attempting to refer to is called Inverse Square Law, but it has nothing to do with short vs long wavelenghts, as wavelength has more to do with quality of light, not intensity.
Inverse Square Law - an overview | ScienceDirect Topics
www.sciencedirect.com
But you keep ignoring how this wave reaches our eyes or plants, dismissing the intensity (length of the waves) factor.
A wavelength is a definition of Wave (type) and length (intensity)
Low intensity light source is called low because the length of the waves being produced is short (compared to a high intensity wave) You can imagine this as a line that gets broken when you lower the intensity
And becomes more solid and longer when u raise it
When I say longer I mean the wave has much more energy behind it to keep the light or wave going without losing same energy
leading to much more saturation at the first places the wave hits and continuing as the line has more power behind him that result in higher ppfd count, which only tell us how much the line is able to reach to a certain plain and when it is absorbe, how much will continue
Light (wave) power (length of the wave).
No light source is different, you have the diode which determines the types of waves, then you couple it with intensity (voltage) to make those wavelengths short or long, depending on intensity you choose
Last thing, the whole problem is that the diodes are intensity limited, you cannot go higher then the rated intensity the same diode or bulb permits
So, we are left with 1 option, change the diodes
Or make them better at handling power that produce their wave types for longer distances without breaking the line or ppfd count
Kassiopeija
Well-Known Member
The oftentimes read claims of Ceramic-MH of "only needing 315w instead of 600w HPS" is also a hoax cleverly designed by the HID industry to weasel around the overtaking of the market by the LED technology. A 315w CMH has only a little better photon-efficacy of a 600w HPS. If their claims would be true, then CMH would be en parre with LED 3.0umol/J but that is simply not true. The CMH prevents some IR/heat emission but with LED now at 4.8umol/J for the latest 660nm diodes that's like a complete new world. Even 2.
@PJ Diaz, some of the HIDs IR emissions do actually greatly transmit through organic matter that is why the 850 & 940nm diodes are used for nightvision telescopy. That type of radiation will basically loose only 10% of it's photon count per incident-of-leaf. Still, it does add extra energy to the system where it does so but is one of the major contributors why HPS/HID can increase metabolism really deep inside the plants' structure. Other wavelengths like around 1500nm - 2500nm are much better to heat up carbohydrates or water swiftly upon contact.
@PJ Diaz, some of the HIDs IR emissions do actually greatly transmit through organic matter that is why the 850 & 940nm diodes are used for nightvision telescopy. That type of radiation will basically loose only 10% of it's photon count per incident-of-leaf. Still, it does add extra energy to the system where it does so but is one of the major contributors why HPS/HID can increase metabolism really deep inside the plants' structure. Other wavelengths like around 1500nm - 2500nm are much better to heat up carbohydrates or water swiftly upon contact.
Kassiopeija
Well-Known Member
no - the wavelength (or frequency) of a photon relates to its colour and thus, its energycontent.
it's the only varying parameter (besides spin) a photon can actually have.
all other considerations arise from the stacking of photons, the number of photons, inside the electro-magnetic field that is light.
Kassiopeija
Well-Known Member
Here you see how wavelength correlates to frequency and energy. It's really simple to calculate as you only have 1 parameter that can change in that formulae
Kassiopeija
Well-Known Member
The 5777K is the colour-temperature of our sun which correlates to a black-body at this temperature
Rurumo
Well-Known Member
CMH is my all time favorite light source, but I've grudgingly switched to LED because its multitude of benefits are undeniable. First off, safety wise, it's nice not having to worry about an exploding ball of molten fire. When the power goes out and the lines try like hell to stay on and flicker like crazy for 30 sec, I'm always glad to be using LED instead of listen to my CMH ballast trying to fire every few seconds but fail because of the hot restrike protection system. Safety aside, the DOUBLE yields are also nice. There is no comparison between HID and LED in terms of yield. More light equates to more yield up until the point another aspect of your grow bottlenecks you. I love the technical discussion, but it comes down to results, and LED has converted most of us old timers who've been using various HID lights for 25+ years. To be honest, I didn't want to like LED, but I'm a pragmatic person, so I'm all in on LED now. Though I do want to see better spectrums in the future.
Kassiopeija
Well-Known Member
it cannot loose energy. That's impossible. It's against the natural laws of energy conservation. It will always have the speed of light and its frequency. Forever. Though the density of photons will get less with distance
but it's just another way to illustrate that *the same amount of photons* now cover/got dispersed over a much greater area - which is increasing not linearily. Since the emitted energy is the same, but the area increases inversely squared, you register a great drop in locale irradiance/PPFD/light density although all lightbeams together measured would still register/mount up to the same energy.