THCbreeder
Well-Known Member
How much do LEDs penetrate the canopy? Anybody have any insight?
LED Penetration?
- Thread starter THCbreeder
- Start date
SupraSPL
Well-Known Member
The light penetrates the first leaf layer by about 10% ( I think greengenes said that). But as far as how far does the light "reach", that depends on the optics. If you run a COB with no reflector and no lense, it will emit in a 120 degree cone. But if you use a 90 degree reflector it will reach much further. And if you use use a 60 degree even further. So the trick is, to match the angle of the cone to the distance from the canopy and the depth of the canopy, to get even coverage without the light spilling out the side.
If the COBs are very close to the canopy, you can go without a reflector and almost all of the photons will make it to the canopy.
If the COBs are very close to the canopy, you can go without a reflector and almost all of the photons will make it to the canopy.
Cococola36
Well-Known Member
Hey Supra, would it be correct to assume with a 90 degree reflector that the distance with vero29 running at 52 watts would need about 24" from canopy? I only have ever used panels with multiple 3watt and or 5watt emitters and ran them about that distance or a bit less.
Greengenes707
Well-Known Member
Te best thing about 90* reflectors is how easy the trig/math to figure out coverage is.
90* means 45 to each side....meaning that there is it is an equallateral triangle...
So that means what ever your hieght is...is also how wide you angle will spread for you to get to half of center intensity.
So on cob 18" using a 90* reflector producing 1000umols should hit 500umols at 18"off center to each side.
As for penetration...
Leds have a great ability to adapt to situations...
If you need as much penetration as a 1k hps...it can be done
If only want a couple inches of penetration...it can be done
90* means 45 to each side....meaning that there is it is an equallateral triangle...
So that means what ever your hieght is...is also how wide you angle will spread for you to get to half of center intensity.
So on cob 18" using a 90* reflector producing 1000umols should hit 500umols at 18"off center to each side.
As for penetration...
Leds have a great ability to adapt to situations...
If you need as much penetration as a 1k hps...it can be done
If only want a couple inches of penetration...it can be done
medicinehuman
Well-Known Member
I agree. So how are people attaching homey made reflectors?
Cococola36
Well-Known Member
ill be honest my man, never made it to trig lol I always got and A in math but since i took the vocational route in high school vs college prep classes it wasn't in my schedule... but good point made as math is math. I think heading towards 1k penetration type realm would be nice
THCbreeder
Well-Known Member
thanks for the response I was wondering about how much LEDs penetrate.
THCbreeder
Well-Known Member
I was wondering how much my XGS – 190 can penetrate. Thanks for the response..
Yodaweed
Well-Known Member
LED's aren't really used for penetration that's why most LED grows use a scrog or sea of green method and trim underneath this way you avoid popcorn and get all big top buds.
GrowUrOwnDank
Well-Known Member
BWAHAHAHAHAHA!
You said "penetrate".
LOL! You said "attaching homey"
ROFL! You said "phallocentric".
"lumenphile" OMFG I can't breathe.
Phallocentric penetrated attached homey the lumenphile.
Meh. Wasn't that funny. Carry own.
PSUAGRO.
Well-Known Member
It's all about lubing up those photons brahhhhhh
reasonevangelist
Well-Known Member
And!: if you're in a smaller area, you'll most likely already have reflective walls (because you learned that already, right?), so reflectors and optics become less important, due to the physical space/positioning requirements of the fixture and emitters themselves, because at about 12" out from the fixture, those 90 degree intensity cones are already almost entirely PAR overlapping... and that PAR @12" footprint is already much larger than the footprint of the fixture itself... and anything not directly bombarding the leaves, is already coming back from the walls... so at that point, it's just about keeping the lamp far enough away to not burn the canopy. But yeah, cobs can certainly penetrate if you design your fixture accordingly. You can also go the other direction and aim for max spread, which has everything getting bombarded by photons from the most different directions (photon angle diversity? lol... anyone ever considered whether such a thing might matter?), so maybe that would help more than "penetration?" Maybe instead of "through," we want to be more like water and "envelop." Maybe the light can sort of... take the shape of the cup it fills, so to speak. I mean, that's pretty much already happening anyway, to some extent. Maybe the plant can use more angular photon diversity, better than it can use more canopy intensity. I tend to think we want as many of the existing leaves as possible, each receiving enough photons to make them worth the nutrients it costs to grow them. I think that's probably 'better' than aiming for maximum penetration. Then again, sometimes you got more vert than horizontal, and so penetration is pretty much the only way... which, ironically (imo) requires you to keep the plant short, because your HD beam will burn it if it gets too close. Maybe a shorter but wider, bushier, thicker plant, is better than a tall lanky one with an impressive cola.
SupraSPL
Well-Known Member
I think I did hear about a study that claimed diffused photons were preferred by plants I will try to track it down.
http://www.dpi.nsw.gov.au/__data/assets/pdf_file/0007/119365/light-in-greenhouse.pdf
"Diffuse light is better than direct light because it is able to reach the lower parts of the canopy (less shadowing) and it will not cause sunburn. Irrespective of whether the light is direct or diffuse, it must be of sufficient intensity (lux). The selected covering material may also be used to increase the amount of diffuse light. A textured surface on glass, for example, can increase the proportion of diffuse light without significantly reducing the total level of light transmitted. On a cloudy day, the majority of the light will be diffuse. On the Central Coast of NSW, the warmer months are characterised by a greater number of cloudy days than the cooler months. This is an ideal situation for greenhouse production."
Sounds like they are suggesting that the diffused light gets used more efficiently because they can reach into more parts of the canopy.
http://www.dpi.nsw.gov.au/__data/assets/pdf_file/0007/119365/light-in-greenhouse.pdf
"Diffuse light is better than direct light because it is able to reach the lower parts of the canopy (less shadowing) and it will not cause sunburn. Irrespective of whether the light is direct or diffuse, it must be of sufficient intensity (lux). The selected covering material may also be used to increase the amount of diffuse light. A textured surface on glass, for example, can increase the proportion of diffuse light without significantly reducing the total level of light transmitted. On a cloudy day, the majority of the light will be diffuse. On the Central Coast of NSW, the warmer months are characterised by a greater number of cloudy days than the cooler months. This is an ideal situation for greenhouse production."
Sounds like they are suggesting that the diffused light gets used more efficiently because they can reach into more parts of the canopy.
medicinehuman
Well-Known Member
HELL, my areas are probably small enough that light bounces all over almost. I was thinking reflectors but I think I'll leave alone for now. Those CLW solar flare like I had seemed to have really good penetration ( for 1 plant), too bad it was so warm running.