Beefbisquit
Well-Known Member
Hmm that's weird because I grew 6 footers with all LED and no supplemental lighting.
I just don't get LED's....Someone enlighten me
- Thread starter lilroach
- Start date
Hmm that's weird because I grew 6 footers with all LED and no supplemental lighting.
No its not, try putting them both on an SPD that allows direct comparison to see the differences. For goodness sakes YOU can see the difference in just the photos of the HPS grows that abound this forum. The HPS is a bunch of phase shifting Orange Yellow light with a ton of heat.
FranJan
Well-Known Member
Sorry Beef you are mistaken here. LEDs do not do full spectrum. They use metamerism to produce white light. You only need 2 to 3 spectral peaks in the right areas and at the right power to produce light that appears white to humans. There is no company putting out full spectrum LEDs since it's not worth it. Efficacy is terrible they say. That's why you have the dip in 500, it's isn't needed to produce white light for us. And if you don't believe me read the Lenks or E. Schubert. They have large sections on how LEDs produce white light. Also Beef when you look at those charts the amount of other colors is so low as to be useless, intensity wise. Even when you run them to spec.
Why does everyone think that if it's white light it's full spectrum sunlight? This place is gonna turn into ICM soon, I swear
. How is white light made with LEDs?
Presently, there are two approaches to creating white light.
Mixed-color white light: One approach is to mix the light from several colored LEDs (Figure 4) to create a spectral power distribution that appears white. Similarly, so-called tri-phosphor fluorescent lamps use three phosphors, each emitting a relatively narrow spectrum of blue, green or red light upon receiving ultraviolet radiation from the mercury arc in the lamp tube. By locating red, green and blue LEDs adjacent to one another, and properly mixing the amount of their output (Zhao et al. 2002), the resulting light is white in appearance.
| Figure 4. Spectral power distributions of several types of LEDs. |
|
| Figure 5. Spectral power distributions of early phosphor-based white LEDs (left), and white LEDs using more recently developed phosphors (right) with increased output between 600 and 650 nanometers. |
|
exactly. The better LEDS are using phospors to do the white and its actually very similar to the phospors used in T5 fluroescent or induction lighting.Why does everyone think that if it's white light it's full spectrum sunlight? This place is gonna turn into ICM soon, I swear.
Spectra varys greatly depending on the phophors used and the target. I have been staying away from LED whites mostly because I can pick a T5 tube with the spectra that I want, while the led industry is either very hush hush its a secret or they use the cheapest crap out there for whites or the units are pricey.
I have seen some very good results with the new R/W Apache led units, but I can't afford them (look for Tags420).
PetFlora
Well-Known Member
Clearly, you ain't up to speed on whites. I am on my second grow using white led tubes + white A19 globes. Captainmorgan has had incredible results using only Cree A19 globes. Check out his grow in the led forum
full spectrum whites depends on your definition. They certainly cover all the PAR mj plants require. That said I mix NW + WW ~3:1 during veg, and 1:3 until flower, then all WW
full spectrum whites depends on your definition. They certainly cover all the PAR mj plants require. That said I mix NW + WW ~3:1 during veg, and 1:3 until flower, then all WW
Beefbisquit
Well-Known Member
what do you mean I ain't up to speed ? You yourself choose the whites that suit your needs. NW versus WW ? Just as I choose my T5 spectras to suit my needs. to fill out my wide spectrum needs.
lol 2200 - 2700k is yellow
Beefbisquit
Well-Known Member
I agree, you can add colours to make white light. If you add green red and blue you get white. If you look at your first chart, you'll notice that all the wavelengths overlap..... creating a full spectrum using different LED's. HPS uses a single filament that prodcuces white light in the 2200-2700k colour range. It's still white light.Sorry Beef you are mistaken here. LEDs do not do full spectrum. They use metamerism to produce white light. You only need 2 to 3 spectral peaks in the right areas and at the right power to produce light that appears white to humans. There is no company putting out full spectrum LEDs since it's not worth it. Efficacy is terrible they say. That's why you have the dip in 500, it's isn't needed to produce white light for us. And if you don't believe me read the Lenks or E. Schubert. They have large sections on how LEDs produce white light. Also Beef when you look at those charts the amount of other colors is so low as to be useless, intensity wise. Even when you run them to spec.
Why does everyone think that if it's white light it's full spectrum sunlight? This place is gonna turn into ICM soon, I swear
How is white light made with LEDs?
Presently, there are two approaches to creating white light.
Mixed-color white light: One approach is to mix the light from several colored LEDs (Figure 4) to create a spectral power distribution that appears white. Similarly, so-called tri-phosphor fluorescent lamps use three phosphors, each emitting a relatively narrow spectrum of blue, green or red light upon receiving ultraviolet radiation from the mercury arc in the lamp tube. By locating red, green and blue LEDs adjacent to one another, and properly mixing the amount of their output (Zhao et al. 2002), the resulting light is white in appearance.
Phosphor-converted white light: Another approach to generating white light is by use of phosphors together with a short-wavelength LED. For example, when one phosphor material used in LEDs is illuminated by blue light, it emits yellow light having a fairly broad spectral power distribution. By incorporating the phosphor in the body of a blue LED with a peak wavelength around 450 to 470 nanometers, some of the blue light will be converted to yellow light by the phosphor. The remaining blue light, when mixed with the yellow light, results in white light. New phosphors are being developed to improve color rendering as shown in Figure 5.
Figure 4. Spectral power distributions of several types of LEDs.
Figure 5. Spectral power distributions of early phosphor-based white LEDs (left), and white LEDs using more recently developed phosphors (right) with increased output between 600 and 650 nanometers.
If it wasn't there would be parts on the graph I posted with zero power in a specific wavelength, you can clearly see that there isn't.
If you take 3 flashlights that have filters over them, one green, one red, one blue and shine them all on the same spot - you still get white light.
Beefbisquit
Well-Known Member
"Color temperatures over 5,000K are called cool colors (blueish white), while lower color temperatures (2,7003,000 K) are called warm colors (yellowish white through red)" -
It's called WARM WHITE LIGHT.
http://www.handprint.com/HP/WCL/color12.html
Im not debating that HPS isn't yellowish - but it's still white light just like cool white light is blueish, but still white light.
tebos
Member
I hope to be able to clarify some things.
Efficiency
HPS has a (radiometric) efficiency of 40%, i.e. 40% of the power drawn is actual light output, which is really good (T5's are at lousy 15%). LED's do already offer higher efficiency with more than 60% (mostly blue LED's).
And because most LED lights are basically blue/red peaking light's with a very little white supplementation to provide full spectrum they indeed are more efficient than HPS because only the photosynthetic important spectrum's are actually drawing power, no light being wasted.
It's important to know that LED's are more efficient at low current...
Price
... hence the usage of lots of emitters being required for efficient usage, which makes the light more expensive.
Saving money with LED's will take a lot of time/runs IMHO, maybe you can save power because you don't have to cool the canopy as much as with HPS.
Temperature
Even if LED panel's would be running at the same efficiency as HPS the cab would be cooler because HPS emits a lot of infrared light, which is heat emitted through light. LED's actually have very little IR - the heat goes straight into the heatsink and not the plants.
CRI is the color rendition index as perceived by the human eye, it's not important for plants. High CRI LED's do have more red in them which is beneficial in white only lights, that's it.
LED's are going to be very interesting in the future for sure
Efficiency
HPS has a (radiometric) efficiency of 40%, i.e. 40% of the power drawn is actual light output, which is really good (T5's are at lousy 15%). LED's do already offer higher efficiency with more than 60% (mostly blue LED's).
And because most LED lights are basically blue/red peaking light's with a very little white supplementation to provide full spectrum they indeed are more efficient than HPS because only the photosynthetic important spectrum's are actually drawing power, no light being wasted.
It's important to know that LED's are more efficient at low current...
Price
... hence the usage of lots of emitters being required for efficient usage, which makes the light more expensive.
Saving money with LED's will take a lot of time/runs IMHO, maybe you can save power because you don't have to cool the canopy as much as with HPS.
Temperature
Even if LED panel's would be running at the same efficiency as HPS the cab would be cooler because HPS emits a lot of infrared light, which is heat emitted through light. LED's actually have very little IR - the heat goes straight into the heatsink and not the plants.
CRI is the color rendition index as perceived by the human eye, it's not important for plants. High CRI LED's do have more red in them which is beneficial in white only lights, that's it.
LED's are going to be very interesting in the future for sure
Bumping Spheda
Well-Known Member
Yeah, but the CRI of HPS is like 17, lol. That's not a very "true" 2200-2700k.
The Grey line is a 2700k blackbody. I have never seen an SPD graph of an HPS bulb that resembles that Grey line in even the slightest possible way. Yes, HPS covers the entire visible/PAR range. You could call it a 2200-2700k White light source. But I'm pretty sure I could also call it a 6000k White light source with a CRI of 2...
The Grey line is a 2700k blackbody. I have never seen an SPD graph of an HPS bulb that resembles that Grey line in even the slightest possible way. Yes, HPS covers the entire visible/PAR range. You could call it a 2200-2700k White light source. But I'm pretty sure I could also call it a 6000k White light source with a CRI of 2...
barcelona100
New Member
In a few days i will post my yield using the led lamp. it wont be huge as we are using only small bushy autos....next time we wont do autos and should get better yield....we went with led because of electric costs with other lights...to have 400w light plus bigger fans would just be far too expensive here.....heat is not a problem for us or smell as we are outside with grow box in a shed within a brick outhouse building....good weed costs about 300 pounds an ouce/ 28 grammes here...maybe 460 us dollars so its dear...if we can get enough nice personal smoke at low cost and know that we are getting organic and can choose the strain etc.......then thats what its all about.....
DadaInhales
Well-Known Member
LED'S!?!?!??!?!?!
[video=youtube;waEC-8GFTP4]http://www.youtube.com/watch?v=waEC-8GFTP4[/video]
[video=youtube;waEC-8GFTP4]http://www.youtube.com/watch?v=waEC-8GFTP4[/video]
GrowinDad
Well-Known Member
I was using CFL and switched to LED. i grow for personal so huge yield not essential. HID scares me and It seems like ballasts and bulbs go out often. CFL got me all I needed but are a pain in flower to keep the bulbs right on the plants. So I am going LED because they can sit above the canopy higher, last forever, no heat, one light for whole grow, min energy use, etc. Yes it cost more upfront but when compared to buying weed, pays for itself in one grow.
All of the technical stuff is great but I am no scientist. What I will say is that thus far I did a 12-12 from seed grow under it to start and harvested this week. I am guessing about 3/4-1 oz per plants and I was happy. Seems a little better than what I got under 14 23w CFL. I am using one Area 51 SGS 160. So for me, cash wasn't an issue and LED does what I need efficiently and easily.
All of the technical stuff is great but I am no scientist. What I will say is that thus far I did a 12-12 from seed grow under it to start and harvested this week. I am guessing about 3/4-1 oz per plants and I was happy. Seems a little better than what I got under 14 23w CFL. I am using one Area 51 SGS 160. So for me, cash wasn't an issue and LED does what I need efficiently and easily.
ak84
Member
Dude... Plasma TV's are so 00s. Don't you know that for this decade even the TV's are all led? LEDs are the future, you guys need to get over yourselves.
Oh and by the way... The reason why most people supplement light on LED grows, is because THEY CAN. If you have almost always low temps, and already use a minimum of watts for your grow, why shouldn't you supplement? It's a win-win to supplement when using LEDS. Also, doing stuff with LEDS is modular, so you can experiment with many different setups all in one grow.
PetFlora
Well-Known Member
If you buy the hype, then yes, plasmas are so 00. If you don't know I am BIG on leds for growin, but my recent experience (< 5 months ago) after buying an led tv was to return it in 3 days. Not that it didn't do SOME things right, but overall, not ready for prime time. I replaced it with a plasma and am very happy
Beefbisquit
Well-Known Member
I find Plasma TV's deliver much better colors than LED.
It's why I also bought a Plasma TV. The new generation of Plasmas don't have the same issues as thew old TV's like image burning..... LED's can't deliver on deep blacks either....
Although I must say my parents Aquos Quattron does have very nice, bright colors!
