Solving the fatal flaw of LEDs - experiment

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I think we can solve the fatal flaw of LEDs (low light intensity at any one point, poor penetraton into the canopy) by focusing their light until we have the same photons directly beneath the light as with a suitable HID. A light bar the width of the garden, a reflective hood designed to focus the light directly down in a narrow strip, and a light mover.

Imagine two types of lights - a 100 photon HID and a 10 LED light that produces 100 photons total. The HID produces light from 1 point and 100 photons hit the canopy from 1 point, giving good penetration. The 10 LED lights each give 10 photons from 10 points, giving less penetration.

If we can focus those 10 x 10 photons into a thin strip we can give the plants the same intensity of light as an hid, if only while the light mover has the light bar over that plant.



I have a Light Rail and an 8' x 3' garden, the far ends of the garden are not in light for some time but the plants on the ends grow great. If we had a 4'x3' garden with a 3' x 6" light bar we could hit the plants with intense light and not have them out of the light very long.



Thoughts? Type of lights we could use? Cree? Type of reflector - will we have to build it? I'm ready to start buying parts for this endevor, but don't know the best parts. All suggestions and info will be greatly appreciated.



Special thanks to forum member justthefacts for correcting my mistaken analogy in another thread. Thinking things through really helped me understand lighting better. Than I did, but not as well as I will. Love these experiments.

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This is an excellent post, really helped me think about light intensity differently.

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by justthefacts

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Light is made of photons. They have no mass and a fixed speed. (the speed of light...whoa i heard of that! )

A "weak" source of light puts out less photons. A Stronger light puts out more photons. Photons travel the same way, regardless of how strong the source of light.

When we talk about penetration of light, we mean how much light gets to the bottom of the plant. If there is less overall light, there is less penetration.

Therefore, add enough small lights, and it has the same ability to penetrate as a large light.

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Hobbes said:

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This is an excellent post, really helped me think about light intensity differently.

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by justthefacts

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Light is made of photons. They have no mass and a fixed speed. (the speed of light...whoa i heard of that! )

A "weak" source of light puts out less photons. A Stronger light puts out more photons. Photons travel the same way, regardless of how strong the source of light.

When we talk about penetration of light, we mean how much light gets to the bottom of the plant. If there is less overall light, there is less penetration.

Therefore, add enough small lights, and it has the same ability to penetrate as a large light.

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Click to expand...

I love your signature..

Interesting idea. I'm goito bookmark this thread and see where it goes

Hobbes said:

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This is an excellent post, really helped me think about light intensity differently.

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by justthefacts

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Light is made of photons. They have no mass and a fixed speed. (the speed of light...whoa i heard of that! )

A "weak" source of light puts out less photons. A Stronger light puts out more photons. Photons travel the same way, regardless of how strong the source of light.

When we talk about penetration of light, we mean how much light gets to the bottom of the plant. If there is less overall light, there is less penetration.

Therefore, add enough small lights, and it has the same ability to penetrate as a large light.

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Click to expand...

Thank you, someone that also is not completely naive to the whole LED mumbo jumbo. I have been following the plight of LED lighting since the start and it has been full of so many people babbling crap like, LED light does not have the same penetration as HID. Well damn, if you are testing a 10w ebay bought LED light with red blue LEDs don't be surprised to see the bottom leaves dropping off. Light is Light and people just don't seem to understand that. The original poster fails to realise that light from a single point will have a single point shadow on lower leaves whereas the LED with multiple point sources will generate less shadows. If one wanted to, one could make a grow room where the LED lights are fixed not only to the ceiling, but to the walls and floor. so this argument of penetration is frivolous and has no basis. the fact that you can mount LED's closer the to plant and in more configurations than simply hanging from above are examples of the potential of LED lighting that just isn't taken into consideration when uneducated people report about their hopeless LED efforts.

sammons said:

Thank you, someone that also is not completely naive to the whole LED mumbo jumbo. I have been following the plight of LED lighting since the start and it has been full of so many people babbling crap like, LED light does not have the same penetration as HID. Well damn, if you are testing a 10w ebay bought LED light with red blue LEDs don't be surprised to see the bottom leaves dropping off. Light is Light and people just don't seem to understand that. The original poster fails to realise that light from a single point will have a single point shadow on lower leaves whereas the LED with multiple point sources will generate less shadows. If one wanted to, one could make a grow room where the LED lights are fixed not only to the ceiling, but to the walls and floor. so this argument of penetration is frivolous and has no basis. the fact that you can mount LED's closer the to plant and in more configurations than simply hanging from above are examples of the potential of LED lighting that just isn't taken into consideration when uneducated people report about their hopeless LED efforts.

Click to expand...

You guys should check out the new issue of Maximum Yield. It is about the second generation Led's. Quad bands capable of penetrating with 2 watt diodes.
The test they ran on a lamp that pulls 586 watts of power showed it kicking everythings ass. Also I guess the new stealth grow Led's are using this new technology.
It may be a disguised infomercial but it is very interesting IMO.

Victory!
Marimaschiac

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I haven't been able to find a light sensor for the two usable sides of PAR watts so I'm going to go with a Quantum meter - measures PAR watts (~400nm - 700nm). The Fieldscout looks excellent.

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"Quantum sensors measure light energy at the specific wavelengths plants actually use for photosynthesis. Start taking more meaningful light level measurements yourself with a low-cost quantum meter.


Fieldscout Quantum Meters Measure light used for plant growth





Light has three principal characteristics that affect plant growth: quantity, quality, and duration. Light quantity refers to the intensity or concentration of sunlight. Light quality refers to the color or wavelength reaching the plant surface. Light duration or photoperiod refers to the amount of time that a plant is exposed to sunlight.

Quantum sensors measure light energy at the specific wavelengths plants actually use for photosynthesis. Research indicates that older lux and foot-candle meters could have error rates up to 45% when used to estimate light quantum available for plant growth. Start taking more meaningful light level measurements yourself with a low-cost quantum meter.

All quantum meters here measure Photosynthetic Photon Flux (PPF) as µmol m-2 s-1 for Photosynthetically Active Radiation (PAR) in the range of 400 to 700 nm. Quantum meters can be used in the field, laboratory, above or below plants, in growth rooms and greenhouses. The meter approximates radiation between 400 and 700 nanometers(PAR) as umol m-2s-1.

Now also available with external sensor on 2-meter cable."

$199 - $299


http://www.specmeters.com/Light_Meters/Quantum_Light_Meter.html

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I'm told by the people at Spectra that I would need a spectormeter and I couldn't find one suitable, Spectra is still developing a hand held model.

http://www.stellarnet.us/products_spectrometers_BlueWave.htm

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Next I need a 200 watt LED panel 32" in legnth, or several PAR38s I can put together to make a light bar.

Could anyone with LED experience suggest a good light please. I'm going to use it in a 36" wide grow cage with a light mover, a 32" panel would work well, any other suggestions would be appreciated.

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Alright so If you would like to solve your light problem, I can helpyou out; although it might be costly. I am a recent saltwater marine aquarium hobbyist. With that said, I have a reef aquarium filled with beautiful fish and exceptional corals. These corals, like plants, need light to survive. DUHHH. Since the lighting system is such an important part of a marine hobbyist aquarium, research has developed for maximum efficiency. The second most recent lighting system used for aquariums is T5HO, which is what I used, and am using for my plants. They grow great. However, the newist an best lighting systems for saltwater aquariums are LED lighting systems. So as for plants, I am going to assume that LED lighting systems will eventually take over the indoor growing industry. For now, the lighting systems are expensive however they are very dynamic and functional. With these lighting systems, each individual LED can be pre-programmed for a certain wavelength, and other such features...

Anyways, all i wanted to say is that if you really want a high quality LED system, check at marine and saltwater stores, either online or in town. They are already produced and can save you the time and effort in building one yourself.
LED is the future: efficient and dynamic

hobbes,

dude.....awesome dedication shown here. here are some links

http://www.ledgrowlights.info/makeLEDgrowlight.php
https://www.rollitup.org/do-yourself/138724-diy-led-grow-lights.html
http://www.instructables.com/community/LED-Grow-Lights_1/
https://www.rollitup.org/indoor-growing/275226-my-upcoming-led-diy-found-2.html

"Make up of an ideal led panel:
2% UVB Leds for resin and tric production. 380mn
6% Royal Blue Leds 455mn
12% Blue Leds 470mn
30% Red Leds 627mn
50% Far Red leds 660mn" from gra.city

http://www.youtube.com/watch?v=6mNuz8QP-VI

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I sent this letter out to a spectrometer company, maybe better luck.

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"Can the Jazz be set to measure PUR watts as well as PAR watts?

I'm doing experiments with LED and HPS bulbs and light penetration into the plant canopy. I would like to know the PUR watts for both types of lights at different levels of the plant. Using PAR watts will give false PUR readings for the HPS bulbs and lead me in the wrong direction. A quantum light meter would be great other than this.

I believe I'm looking for a spectrometer that measures intensity, but I have virtually no experience with spectrometers/light meters - if you could offer some advice I would appreciate it.

Thanks."

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Jaz is like nothing you’ve ever seen before -- a community of stackable, modular and autonomous components that combine to create a family of smart sensing instruments. Jaz is unfettered by the limits of traditional optical sensing instrumentation. Its unique features and expandable platform makes it uniquely suited for field applications, remote sensing, process flow and quality assurance.
Jaz is also available with an LED module that allows you to switch out LED bulbs much more easily. Now, instead of having to replace the entire module, all that’s necessary is to replace the LED assembly – a small fixture with just three screws to manage. We offer modules and bulbs for white LEDs and for 450 nm, 590 nm and 640 nm wavelength LEDs. Consult an Applications Scientist for details.

• Rechargeable Lithium-Ion battery
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• Ethernet connectivity plus an SD card for data storage make remote operation a snap!

http://www.oceanoptics.com/Products/jaz.asp

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Perfict: Alright so If you would like to solve your light problem, I can helpyou out; although it might be costly. I am a recent saltwater marine aquarium hobbyist. With that said, I have a reef aquarium filled with beautiful fish and exceptional corals. These corals, like plants, need light to survive. DUHHH. Since the lighting system is such an important part of a marine hobbyist aquarium, research has developed for maximum efficiency. The second most recent lighting system used for aquariums is T5HO, which is what I used, and am using for my plants. They grow great. However, the newist an best lighting systems for saltwater aquariums are LED lighting systems

Perfict thanks for the heads up, I'll look into these "LED"s you mentioned. Sound like just what I'm looking for for this experiment.



On a different subject, what strain(s) do you have? I'd like to look into them.

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"here are some links

http://www.ledgrowlights.info/makeLEDgrowlight.php
DIY LED Grow Lights
http://www.instructables.com/communi...Grow-Lights_1/
My upcoming LED DIY, and found some 660nm red led's for you DIY'ers

"Make up of an ideal led panel:
2% UVB Leds for resin and tric production. 380mn
6% Royal Blue Leds 455mn
12% Blue Leds 470mn
30% Red Leds 627mn
50% Far Red leds 660mn" from gra.city

http://www.youtube.com/watch?v=6mNuz8QP-VI"

Thanks dtp, I'll look into those tonight and post after I review them.

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Keep it up hobbes, your experiments are always intriguing and original

hobbes- put this in your jar and let it cure for a min-

Led's emit a focused beam of light, an LED consists of 3 components- a diode, a resistor, and a lens. think of a simple flashlight, emitting a beam of light in the dark.

Now back to photons-
justthe facts left out a very obvious thing about the nature of photons. I will reiterate just for prudence's sake.
Photons travel in one direction, and one direction only. That direction is a perfectly straight line, the term 'ray' used in mathematics, describes the path of a photon perfectly.infinitly straight. only a star has enough gravity to alter the path of a photon. and even then it is a very very slight bend, almost unmeasurable except over great distances. einstein predicted this ages ago and it has been confirmed, those of us that follow physics know the rest of the story.

now on photons and led's-

Led's emit photons on a path perpendicular to the plane of the led (90 deg angle) this is achieved by the lens on the led. the diode itself emits light like any other substance,. its radiated. however the radiated light is weak, so it is focused and directed by the lens that caps the diode. a good example of this principle is the headlights on your car... tiny lamp, burns bright but weak, is focused into a powerful cone shaped beam.... the center of the cone is packed very densly with photons, but as you get to the edges of the beam, the density very rapidly diminishes. if you had magic photon glasses and happened to be looking at a led panel that was lit, it would look like it was standing on dozens of little cones, one cone for each LED in the panel. And that is the flaw of the LED. the lens directs the emitted light in one direction only, down. (or wherever your pointing the panel at.)

now take your magic photon glasses and look at an hid lamp. you might want to crank the settings up on the glasses though first. the photon emission will look like a giant sphere, (like a star! like the sun!) the light is radiated in all directions at an intensity that is very dense with photons. photons are traveling at angles that are perpendicular to the core of the lamp. since the core of the lamp is gaseous, this singular point of emission is speherical in nature, so photons are emitted in all directions; whereas in LED's the photons are focused into one direction. This deflection of light, coming from different angles, is what achieves canopy penetration, not the intensity of the hid lamp, which is almost universally assumed by many. This is also the reason many people acheive success growing with CFL's and HO lamps... the light is emitted from more than one direction, just as found in nature.

If you could find a way to direct the LED light to the lower portion of the canopy, then i think a person could have great success with LED's, or perhaps build a cab with 360 deg LED lighting, then you might have something. ''
But its hard to overcome physics...

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Excellent Iamstoned, explained in one and two sylable words so even the simple minded as myself can understand. Great analogies. I've read your post through 3 times, I'll go over it again tonight when I'm off work then do some research on the issues before I come after you for more info.

"If you could find a way to direct the LED light to the lower portion of the canopy, then i think a person could have great success with LED's"

I believe I have. It's the intellectual equivalent of using a funnel to pour water into a bottle, then a robot to move the funnel and water to the next bottle.

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exactly. need a mover that moves in XYZ dimesions


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or reflectors that perform at < 98% efficiency (ha i wish!)

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With the third phase of the experiment I'll only need X travel on the light meter

(B bb bbback and forth for you g ggg graph hh h handis. J jjj JJ Jackasses.)



Not you Iamstoned, or anyone else on here. I've just been dying to get that one in somewhere. Anyone who doesn't get the reference should perhaps think about investing a bit more time into sometimes socially relevant adult cartoons! J jjj jJj Jackass!

(the thing I loved about that show was the crippled kid was the meanest discriminator, even though it was only gingers. Jimmy and Clyde make that show, excellent actors.)

I've got to find or build some custom equipment, very simple custom equipment thankfully.

That's the third phase of the project, could you help be get a 200W by 32" led light bar; and do you know much about Quantum Light Meters and Spectrograph? I'm in desperate need of a meter that will read PUR watts.

Again, thanks. Any time you browse the thread please correct my mistaken assumptions if you have the time, it's a great help when learning in a vacuum.

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ill do some diggin, and check back in tonite.

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These charts shows the incredible difference in PUR and PAR watts for different types of bulbs. In some cases the PAR watts are twice the PUR watts.

http://www.aquabotanic.com/lightcompare.htm

what if the light had some of the leds up above the plants, but other LED's hung down into the middle of the canopy or underneath...

you know like ...

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i really think a custom built led is the best way to go....

the premade ones do not spread the led's around enough...or have the concept described above. side light from all angles is a must for efficiency. and this idea of dropping them down into the middle of the canopy or even underneath the canopy might be great! no light mover needed in 3 dimensions