kmog33
Well-Known Member
No...and people hopped onto cob and led strips initially Because no one understood the benefits of far red and Uv at the time. Leds have gotten better recently but de/cmh combo still wins in big spaces...
Bars vs Boards
- Thread starter budman410
- Start date
wietefras
Well-Known Member
But that's just it. Since boards are already mounted so high there is no difference in uniformity. At 18"or 24" you really cannot tell the difference between 4 COBS or a few hundred medium sized leds mounted on the same size heatsink.
In fact it's already hard to see the difference between a single big COB and a board in the middle of the same sized tent.
Not? You hang strips at 18"or 24" or 36" even? I doubt that. That's the height boards need to distribute the light evenly. When used as advertised. Strips can be easily at half that height for the same distribution. That's a big difference in wall losses. This will give you 10%, 15% or even 20% extra light on the plants depending on size of the grow.
wietefras
Well-Known Member
Measured in what metric? Power usage? Heat production?
Rocket Soul
Well-Known Member
Lol. I saw Random 3rd nerded this already...
I find amazing this debate still and neither owning up to pros/cons of their own approach.
Boards: of course you can get it even if you have enough. But if youre using premium boards like highlights it will cost you some. Maybe with china boards at 30$ you can splurge and get your spread right. Price is always a factor. But at least it offers a solution for corners...
Strips: somewhat better spread than a 550 of course. But if you are using a homogeneous diode density there is allways going to be some dropp off around the sides and some centre hotspotting, especially if you need to hang it higher: the higher you hang it the more cross lighting in the middle; although in a reflective tent this is somewhat taken care of. But still, if you just do a homogeneous diode density light then youre basicly just building a really big board.
You can either increase diode density in the sides (@Airwalker16 has nice pics of the fissioning boards that achieve this although its only on a single board basis, if you wall to wall these boards there will be some hotspottingg anyways) or make the light slightly larger than your cannopy (and losing light...)
If you use boards you can achieve fairly good evenness for those bigger than 2 but smaller than 4' spaces. A square 3x3 i feel your best bet is getting one board in each corner at around 80w and adjust until happy with spread and hanging height.
Or you can use a 2 driver and strips approach, with one driver for the centre strips and another for a perriferall circuit. On this fixture the strips in the middle, all the way out to the mono strips are lit with one driver (here on low) and the 8 strips bordering on the perifery is on another driver (here on high, you see how the lit diodes look slightly larger due to higher watt per diode).
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Prawn Connery
Well-Known Member
Christ on a stick! Can you not get it through your obtuse grey matter that there are lots of growers – including myself, @Frank Cannon, @Or Gro, @Randomblame (to name a few off the top of my head) – who run wall-to-wall boards at low currents and high efficiencies, hung at 12" or lower?
Is it that advanced that you simply cannot comprehend anyone doing it?
What is so hard to understand about covering your tent roof in panels? Money? We're not all as poor as you, mate!
Moflow
Well-Known Member
Beef curtains Lol
Prawn Connery
Well-Known Member
I don't see any boards hung at 18", 24" or 36" here. In fact, they would be a lot lower if it wasn't for the UV bulbs which need to sit a bit higher to maximise their spread.
You seem to be incapable of thinking outside your own box. There are many, many ways to light a grow room.
Indeed, I see a pattern developing. You know nothing about Dialux, so it is "shitty". You can't comprehend that growers would deck their rooms out in wall-to-wall boards so it is "impractical". These two trains of thought have one thing in common: denial in the face of overwhelming evidence.
wietefras
Well-Known Member
Irony
You keep on ranting hypothetical situations. While I'm talking about real fixtures being sold. Or DIY with a fair comparison of components. Rather than proposing a board solution that costs up to four times as much as the same done with strips.It's really simple, two strips give better light spread than one board. On top of that, two strips actually cost about half of what one HLG board costs.
I understand that you are desperate to sell your crap, but why not simply stick to a fair comparison? One board vs 2 strips or 4 COBs. That's how it works in practice. That's a fair comparison. Even though the board is then still twice the price I guess.
Prawn Connery
Well-Known Member
^ Is this your quote? I see no reference to cost or affordability in that statement.
What I do see is you making a lot of claims and then having to back-track and try to quantify those claims by introducing new parameters.
There are no rules to this debate: you make a statement, you back it up. If you can't back it up, you lose. Do you think the growers who are using wall-to-wall boards care about cost? No. They want the best coverage they can buy. And the best coverage they can buy is . . . a room full of LEDs.
You say "two strips give better light spread than one board" – what do you mean by that? That they deliver the same PPFD across the same surface area? Are you telling me 2x 25W strips are a better light source for growing than a 150W board?
Please provide "real-world" examples then. Oh, that's right: every time someone asks you to back your argument with proof, you have none!
P.S. I'm still waiting to see those super-duper PAR map simulator programs your wrote. Just like I'm waiting to see all those PAR maps you've done that prove your claims.
You are all talk, talk, talk . . .
Prawn Connery
Well-Known Member
What is hypothetical about the photos I've posted up?Irony
They are real grow rooms. Do you pretend otherwise?
Rocket Soul
Well-Known Member
Big lols on those swedish curtains, never heard the expression and now that i remember theyre in every house over there...
wietefras
Well-Known Member
Yes, that;s me trying to explain something to you, but you only cry.
I explained how it's simple logic that spreading light points improves uniformity. If not then why bother with boards? Just clump all leds in the center of the room have point to PAR tests done. Actual test, not some paint lookalike program with useless charts with no context.
I explained over and over that I'm talking about a fair comparison, not some nonsensical, oh but if I splurge out I could achieve the same with a lesser components.
Enough proof, enough to help you understand and I get that you are only in this because you want to sell stuff, but that's not how it works.
Sorry man, I can't help you. You just put your head so much in the sand you cannot see the simple facts presented for you
If you want proof then create it yourself. Since that's the only thing you accept anyway. 2 strips vs one HLG board in a 2x2 tent with reflective walls. The two strips properly spaced at 9" up for all I care vs the HLG board in the center at 18". Same PPF (say 28
from both. How much is left at the canopy?Or if you are able to do this try to calculate the correct hanging height for each solution.
Mrgoodsusa
Member
It's strange so many nerds on this site and none of them are speaking about this interesting topic
cobshopgrow
Well-Known Member
we have 3rd opinion.
wietefras
Well-Known Member
That's not really the issue though. The leds are the same clearly, but the point is that hanging height matters for the amount of light lost on the walls.
Ledgardner did a PPFD map of a HLG board in a 2x2 tent and he registered only about half the photons that were supposed to have been emitted from the board according to the specs. So half the light was lost on the walls. Similar tests with bar lights at much lower heights show much less loss.
For instance Migro did a PPFD map for Chilled GrowCraft X6 and that one lost "only" 15% of it's light on the walls. Part of that is spec vs actuals and the latter was in a larger tent, but still in a tent hanging height matters a lot.
cobshopgrow
Well-Known Member
not disagreeing there.
think in the quote it was just pointed out that you can achieve a perfect spread, same hanging height, both ways.
end_of_the_tunnel
Well-Known Member
Well for me, the issue was seeing a few (not many) posters in various places bring up "penetration" of certain lights/sources as an arguement for being pro that approach. That is cob/puck/ high hung compact boards. Anytime, if ever, someone countered it would be to "argue" the pro's of uniformity of spread that a larger fixture could provide. I repeat, uniformity and spread. No addressing of the "penetration" claim.
Well two posters have pointed out canopy leaf density/Leaf Area Index is what impacts penetration. Still think theres something going on with those few growers who cite a preference for "penetration" with point source type light. Maybe the growing is easier under them as plants are not getting an even blanket, but rather a "spots" and so a plants processes are not under the same strain? photosynthesis - respiration - transpiration. Bit like those lizards I used to catch as a child would leave a piece of wriggling tail in my hand whilst they ran off into the undergrowth. The system could counter and compensate. Regrow anew.
Maybe the OP has his answers now. Spread and uniformity with a bar fixture that dimesionally covers a larger area whilst being hung lower. Or other product. What counts is photons hitting leaves. Not hitting non growing surfaces and dissipating that energy.
Mrgoodsusa
Member
Is that 4x4 fixture? Is that enough red to cover a 4x4
DankaDank
Well-Known Member
There is a reason that Fluence has had the Vyper for as long as they have had the spyder.
Strip lights are actually designed and best utilized for multi tier growing where there is no reflective walls and light needs to be concentrated in a certain area without the use of lenses due to height restrictions.
When it comes to large rooms with a single canopy and minimal or no walk ways it really doesn't make sense to use low hanging rack lights as the shape of the light is barley important when hanging multiple lights at higher heights to create a photon blanket.
When it comes to grow tents things get complicated.
Strip lights are almost always going to lack diode density at the corners and sides when hang at their optimal hanging height. when lifted to try even out spread, wall loses are more sever due to many diodes being positioned close to the walls of the tent thus more of the light hits the sides and more importantly from the "power band" 0-60 degree radiation angle.
Like others have said in a tent you want little LES in the middle and more LES to the sides and corners but not to close to the sides/corners as to interfere with the radiation pattern. People don't understand that LEDs emit different amounts of light at different angles from the center of the emitting surface.
Below is a dialux simulation I made of 8 V22's positioned in 2 groups of 4 cobs centered per 2x2ft area in a 2x4ft area. 330 total watts, 2.5μmol/w 90% reflective walls and an 18inch hanging height.
Despite cramming 2 groups of 4 cobs together, it has better coverage than most strip lights at 6 inches above plant canopy.
Regarding penetration I think GM and GG touched on it well at 2:22:45 in the vid below.
Strip lights are actually designed and best utilized for multi tier growing where there is no reflective walls and light needs to be concentrated in a certain area without the use of lenses due to height restrictions.
When it comes to large rooms with a single canopy and minimal or no walk ways it really doesn't make sense to use low hanging rack lights as the shape of the light is barley important when hanging multiple lights at higher heights to create a photon blanket.
When it comes to grow tents things get complicated.
Strip lights are almost always going to lack diode density at the corners and sides when hang at their optimal hanging height. when lifted to try even out spread, wall loses are more sever due to many diodes being positioned close to the walls of the tent thus more of the light hits the sides and more importantly from the "power band" 0-60 degree radiation angle.
Like others have said in a tent you want little LES in the middle and more LES to the sides and corners but not to close to the sides/corners as to interfere with the radiation pattern. People don't understand that LEDs emit different amounts of light at different angles from the center of the emitting surface.
Below is a dialux simulation I made of 8 V22's positioned in 2 groups of 4 cobs centered per 2x2ft area in a 2x4ft area. 330 total watts, 2.5μmol/w 90% reflective walls and an 18inch hanging height.
Despite cramming 2 groups of 4 cobs together, it has better coverage than most strip lights at 6 inches above plant canopy.
Regarding penetration I think GM and GG touched on it well at 2:22:45 in the vid below.
Lockedin
Well-Known Member
If PAR is lost on the long edges - and even more on the corners; why not address that? Why not drop edges & corners lower (or use cobs on the corners)? Just keep the lower board from casting any canopy shadows (above appx. 110 deg. should be ok).
Tilting edge strips / boards / cobs inwards, or using a mirrored "barn door" would redirect light from a much shorter distance than a wall and result in less loss (still large loss, but less), and more control.
Look at a studio grid / catwalk system - lights are individually dropped and tilted to the required levels, and excess light is cut or redirected with a "barn door" & "flag" setup for complete control. Some larger grids will have secondary levels "greenbeds" that accommodate ganged banks of lights (Ten 18Kw 5600K for instance). Power is centrally located in the dimmer room. (VERY oversimplified - I only did a bit of lighting.)
For our needs, we avoid narrow beamed spotlights in favor of a soft flood --- which is great until we hit the edge of the scene - uhh canopy.
Just like the studios,nobody we only want to light the scene / canopy for the best effect.
Unlike the studios, we don't want to absorb or cut the light (usually) - we want to aim / redirect as many photons as possible, as evenly as possible.
I'm going to cobble together a mirrored barn door when I get a min or two.
The object is to intercept photons on their way to the wall and redirect them earlier, more effectively, and controllably.
Probably did a terrible job describing it - and I'll do an even uglier job assembling it - as long as it's safe and does what I hope it will.
I'll post a few pics either way.
Tilting edge strips / boards / cobs inwards, or using a mirrored "barn door" would redirect light from a much shorter distance than a wall and result in less loss (still large loss, but less), and more control.
Look at a studio grid / catwalk system - lights are individually dropped and tilted to the required levels, and excess light is cut or redirected with a "barn door" & "flag" setup for complete control. Some larger grids will have secondary levels "greenbeds" that accommodate ganged banks of lights (Ten 18Kw 5600K for instance). Power is centrally located in the dimmer room. (VERY oversimplified - I only did a bit of lighting.)
For our needs, we avoid narrow beamed spotlights in favor of a soft flood --- which is great until we hit the edge of the scene - uhh canopy.
Just like the studios,
Unlike the studios, we don't want to absorb or cut the light (usually) - we want to aim / redirect as many photons as possible, as evenly as possible.
I'm going to cobble together a mirrored barn door when I get a min or two.
The object is to intercept photons on their way to the wall and redirect them earlier, more effectively, and controllably.
Probably did a terrible job describing it - and I'll do an even uglier job assembling it - as long as it's safe and does what I hope it will.
I'll post a few pics either way.
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