Which part of the arc? And how do you quantify your "single source" theory when in fact the emissions along the arc are not linnear due to the fact the hottest part of the sodium gas is near the electrode – hence why double electrode HPS arcs are more efficient than single.But it’s not the electrodes In an hid lamp that are the source it is the arc which is a single source.
Firstly, it depends on the translucence of the individual leaf. Even if the leaves are somewhat translucent, your light might only be able to penetrate one leaf before it is blocked by the second leaf.My secondary point was that seeing as the single source will have a hotspot in the Center then more light will pass THROUGH (not around) the leaf under this hot spot than it would if there were multiple sources delivering the same number of photons more evenly across the canopy
Athmospheric scattering is irrelevant in a grow. Distances are much too short for it to have any effect. Wall losses are a thing. I would want to see reflectors on led fixtures.This doesn’t seem irrelevant to me, are you taking into account Rayleigh scattering. And also there is so much more reflection happening with a rail fixture hung high than say a cob or hid. Most peoples grow linings are less than the initial 98% claim which doesn’t take into account contaminants that are statically collected on said lining.
it is because the light will loose only a tiny fraction of its energy but ultimately each photon will still drive photosynthesis equally as it only needs 680nm or 700nm even 780nm to do soThis doesn’t seem irrelevant to me, are you taking into account Rayleigh scattering. And also there is so much more reflection happening with a rail fixture hung high than say a cob or hid. Most peoples grow linings are less than the initial 98% claim which doesn’t take into account contaminants that are statically collected on said lining.
Plants are 3-dimensional though leaves may be appromixated to a 2-d plane.I’ve had no option but to argue the same point for so long which makes me look like a mad man or someone with an agenda. But that’s because I believe what I initially said to be the truth. The point I made certainly doesn’t warrant the amount of times I’ve had to defend myself about it. I stand by it, and I’ll say it again lumens can’t be added because they come from a single source only lux can be the cumulative value.
I’ve also said many times that cobs are closer to single source than qb panels and qb panels are closer than qb strip rail fixtures. But it’s not the electrodes In an hid lamp that are the source it is the arc which is a single source.
It certainly makes me look like an idiot to newcomers of the thread, who are just reading a couple pages with other peoples reply’s which insinuate I’ve bashed led vs hps when I’ve never at any point done that.
I 'm not sure I follow. I would think a point source radiates in a sphere to all directions.Plants are 3-dimensional though leaves may be appromixated to a 2-d plane.
A singular point light-source is 1-d.
though there is some merrit to his point as leaves can be somewhat flexible and react to the light environment. for example, there have been studies comparing leaf chlorophly content indoor vs outdoors and outdoors had way less, so a leaf would allow more light to transmit through. which, considering outdoor the sun is way more harsh, is a method of protection when still being able to run photosynthesis at a max speedFirstly, it depends on the translucence of the individual leaf. Even if the leaves are somewhat translucent, your light might only be able to penetrate one leaf before it is blocked by the second leaf.
This also assumes that the light intensity is such that it is able to pass through a leaf without causing irrepairable damage to the cells as the light imparts heat energy as it passes through. Just how long those leaves would survive without burning would depend on the variety of plant.
this is in response of his claim about "but lumen not lux"... like you posted correctly pages ago "lux is lumen over area". he still doesnt get it and is transfixed at a very base formulae that does nowhere correctly describe the situation as isI 'm not sure I follow. I would think a point source radiates in a sphere to all directions.
and I’ll say it again lumens can’t be added because they come from a single source only lux can be the cumulative value.
If he is talking about a "single source" then the only "true" single source of light must be a single photon emitted by a single atom/molecule – all other sources of light are a combination of photons emitted from a cluster of atoms/molecules. Each of those atoms/molecules occupies a different position in space/time, so therefore these clusters cannot all be from the same SINGLE SOURCE.this is in response of his claim about "but lumen not lux"... like you posted correctly pages ago "lux is lumen over area". he still doesnt get it and is transfixed at a very base formulae that does nowhere correctly describe the situation as isHorselover fat said:I 'm not sure I follow. I would think a point source radiates in a sphere to all directions.
Single source = single source of excitation i.e arc vs multiple sources of excitation I.e many semiconductorsIf he is talking about a "single source" then the only "true" single source of light must be a single photon emitted by a single atom/molecule – all other sources of light are a combination of photons emitted from a cluster of atoms/molecules. Each of those atoms/molecules occupies a different position in space/time, so therefore these clusters cannot all be from the same SINGLE SOURCE.
To wit: a single photo emits in only one direction.
Addendum: a single photon may have a wavelegnth that falls outside 400-700nm, so is not even guaranteed to be counted in terms of "luminous flux".
If you are going to stick to the dogma of "single source" then you have to be true to its definition. An arc tube, by definition, emits multiple photons from multiple sources of individual ions. Each of those ions is a "single source" of light (electromagnetic radiation).
@Blue brother – what are the parameters of your "single source" argument?
I totally understand it, we all know that reception is cumulative. I made one point and yes it was lexically semantic, but I only said it once, more of an fyi. Somehow you either think that lm is the same as lm/m2 or you wanna hang me for being semantic. Which is it? What don’t u think I get?this is in response of his claim about "but lumen not lux"... like you posted correctly pages ago "lux is lumen over area". he still doesnt get it and is transfixed at a very base formulae that does nowhere correctly describe the situation as is
I totally agree and haven’t ever and would never say anything to the contrarythough there is some merrit to his point as leaves can be somewhat flexible and react to the light environment. for example, there have been studies comparing leaf chlorophly content indoor vs outdoors and outdoors had way less, so a leaf would allow more light to transmit through. which, considering outdoor the sun is way more harsh, is a method of protection when still being able to run photosynthesis at a max speed
but still, the higher you blast the tops the more will be lost as heat that's why a uniform spread is way better than hotspots coming from individual strong lightsources
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.
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.
Yeah I am.When you find yourself in a hole, stop digging!