A Curved Shaped LED Light

thewaytogrow

New Member
I just happened to run across this new LED grow light that is arc shaped. Have you guys ever heard of this? I have been growing a lot of plants, and have the Diamond Series LED (from the same makers), but I'm wondering if I should switch to this one. What do you think? Here's the link so you can see what it is. http://kck.st/1d5wim9
 

CaliJoe

Member
Well, it isn't out yet, and they don't specify the spectrums used in the colored LEDs, but other than that it looks like a very nice light and a good price if your willing to wait a few months to get it.
 

Bumping Spheda

Well-Known Member
Would be dank if the reflectors/collimators were square some how so you could match your grow space perfectly by finding the right panel height. <<< Set it and forget it mentality. It would also make buying multiple panels and lining up their square beam angles/footprints easy-peasy allowing for easy expandability for any sized grow room. This type of panel would increase the average level of LED penetration, too, by invariably hitting plants with light from multiple angles.

Good idea at heart, odd approach and final design, not necessarily a bad deal or product, however. That's of course just in my opinion.
 

Abiqua

Well-Known Member
Are they phosphor coated Cree's?

It's a cool light, they started a Kickstarter campaign for the lights to try and get them built stateside I guess, through pre-ordering. Looks like they are going to do it too easily. Its only been up for a week or so and they are half way through.

I am thinking heavily about multichip lights, but as DIY, so in that aspect, its a lot of coin for the specs.

What is concering is on the kickstart they say it outputs >80% more Par than a "higher wattage" HID fixture. Above this statement is a FLIR camera image comparing the [4 light fixture, I am assuming] against what they say is a 400 watt HPS. My question is "yeah, but a what height"? Other parameters?

176 real watt fixture putting out 86% more 'usuable' PAR than a 400 watt fixture seems dubious.

Still the dimming is great, looks like cool form factor, but it has me on the fence as a tad gimmicky, but I bet it puts 95% of other fixtures in the same wattage in the rear view mirror.
 

Bumping Spheda

Well-Known Member
Was gonna say PAR has to do with spectrum, but I know jack about all that technical light measurement mumbo jumbo. It all just seems circumstantial to me, I don't know what to make of a umol/s rating w/o seeing a spectral analysis graph, or at least stated radiometric output percentages of given wavebands. Am I the only one :confused:?
 

CaliJoe

Member
Honestly, I have come to hate PAR as it is about as useful as Lux due to the reasons you stated. A Red/Blue light putting out 800 PAR is equivalent to around 2000w of MH if you simply measure the same spectrums, but of course the MH will have more spectrums overall than a red/blue light. Then you add warm white LEDs to the mix and all bets are off, you simply can not make any type of legitimate comparison unless you have a way to break down every spectrum/intensity and show individual numbers for specific spectral output, but we don't have that ability at home. This is why I have come to hate PAR, people seem to put so much into PAR #s when in reality it is a crude form of measurement that can't really make fair comparisons between different lighting technologies. It is best used to compare bulbs within the same technology.

In the pictures above, I compared a 10k XM MH bulb to a DIY Cree LED light with optics, but I used the same electric setting and the LED light has much more blue output, so in reality, the LED PAR reading is actually quite a bit higher than what is pictured. Changing it to 'Sun' mode gives you a more accurate reading with LEDs, and adds about 100 PAR to the number, then doing the math corrections for the blue spectrum adds another 200 PAR to the light, so the LED output is closer to 2200 PAR vs 800 PAR, but to my eyes, the 400w MH actually looks brighter because most of the spectral output is in the yellow range, which does very little for photosynthesis.
 

Bumping Spheda

Well-Known Member
most of the spectral output is in the yellow range, which does very little for photosynthesis.
And yet HPS is the light to beat... It's like quantum physics vs magnetism, it makes absolutely no sense. Perhaps it's similar to the correlation of Green light and high fluence rates? At low fluence rates Green light seems to almost inhibit photosynthetic activity. However, at high fluence rates the Green waveband seems to increase photon uptake... What if there is an odd relationship with Yellow/Orange light?

Idk. I feel I'm pulling at straws in desperation, but how does
hps-250w-spectrum-analysis.jpg
equate to 1gpw? Like... what?
 

PSUAGRO.

Well-Known Member
And yet HPS is the light to beat... It's like quantum physics vs magnetism, it makes absolutely no sense. Perhaps it's similar to the correlation of Green light and high fluence rates? At low fluence rates Green light seems to almost inhibit photosynthetic activity. However, at high fluence rates the Green waveband seems to increase photon uptake... What if there is an odd relationship with Yellow/Orange light?

Idk. I feel I'm pulling at straws in desperation, but how does
View attachment 2793796
equate to 1gpw? Like... what?
This is what I come back too as well^^^ Quite the conundrum;-).........................the reality is that Lumens(per watt) DO matter.
 

mc130p

Well-Known Member
I think a large difference comes from the way in which light is produced in different lights. The arc in HPS bulbs could be almost modeled as a point source of light (with nearly 1/r^2 decrease in intensity), whereas an LED panel has the light production spread out over a large area, with many small light sources (many, different 1/r^2 intensity decreases). Soooo, I think most of the difference comes from overall intensity. LED's will(are?) outperform HPS once they become powerful enough to overcome the penetration difference, especially since they are able to create light in the most useable form for plants.
 

lax123

Well-Known Member
Hi, Calijoe have u ever made tests with and without those optics (which angle?), would be very interested if some lenses would improve im DIY fixture as they also absorb some light and decrease Output.
 

CaliJoe

Member
Personally, I don't agree that HID lighting is 'the light to beat'. Looking at a spectral graph for any MH/HPS bulb you can see it has major shortcomings, so how can that be the light to beat? I have been experimenting with LEDs for over a decade now growing various different things with them. This is my first time growing MJ with them though, but to me a plant is a plant and how photosynthesis works doesn't vary much between them.

This was the first LED grow light I made for a friend who wanted to grow super hot peppers. I used a 3:1 Red:Blue ratio and from his postings on various pepper forums his peppers had the biggest leaves and bushiest plants they had ever seen. He also used/grew under CFLs and sunlight to compare against, and it wasn't even close to a fair comparisons, LEDs outgrew the other methods he tried by far.







And over the past decade I have also experimented with growing algae under various lights (CFL/T5HO) and LED combinations.. conclusion, 6:1 660/455 out grew all other spectrums by a factor of 2 easily.

Warm whites


Red + White vs Red, White, and Blue




6 660nm Red + 1 455nm Blue


Over 1lb of algae grown in 7 days under Red/Blue LEDs, compared to 1/4 pound under CFL/T5, and 1/2 pound under other LED combinations.


a mixture of the colors of the visible spectrum. Here is a summary of wavelengths (nm). If you are building your own LED Grow Lights it may be of help when selecting LEDs for your project.

200 - 280 nm UVC ultraviolet range which is generally harmful to plants. LEDs in this spectrum are non-existant or very expensive.

280 - 315 nm Includes harmful UVB ultraviolet light which causes plants colors to fade. UV LEDs in this range are now available and coming down in price.

315 - 380 nm Range of UVA ultraviolet light which is neither harmful nor beneficial to most plants.

380 - 400 nm Start of visible light spectrum. Process of chlorophyll absorption begins. UV protected plastics ideally block out any light below this range.

400 - 520 nm This range includes violet, blue, and green bands. Peak absorption by chlorophyll occurs, and a strong influence on photosynthesis. (promotes vegetative growth)

520 - 610 nm This range includes the green, yellow, and orange bands and has less absorption by pigments.

610 - 720 nm This is the red band. Large amount of absorption by chlorophyll occurs, and most significant influence on photosynthesis. (promotes flowering and budding) The ratio of red (660nm) to far red (730nm) in sunlight is about 1.2:1

720 - 1000 nm There is little absorption by Chlorophyll here, but Phytochrome uses a nice portion. Flowering and germination is influenced. Near and above the higher end of the band is the Infrared spectrum, which can also be heat and could cause elongation or affect water absorption/transpiration.

Many of these plant pigments have dual wavelength peaks that can be activated with led light combinations:The visible colors of light from shortest to longest wavelength are: violet, blue, green, yellow, orange, and red. Ultraviolet radiation has a shorter wavelength than the visible violet light. Infrared radiation has a longer wavelength than visible red light. White light is

Beta-carotene 450nm 480-485nm dual peak
chlorophyll a 430nm 662nm dual peak
chlorophyll b 453nm 642nm dual peak
phycoerythrin 590nm single peak
phycocyanin 625nm single peak
 

CaliJoe

Member
Hi, Calijoe have u ever made tests with and without those optics (which angle?), would be very interested if some lenses would improve im DIY fixture as they also absorb some light and decrease Output.
PAR without optics on my first grow light


PAR with 80 degree optics
 

tags420

Well-Known Member
I love where this thread is going.

Par is intensity alone. Then spectrum is the other half of the indoor lighting equation.
(correct spectrum) + (right/high intensity) = GROWTH
That is a vague way to look at it but if you change a variable then it could have a big effect on the end(growth).

For example of what advance led is claiming ...Lumigro claims more parbut it's actually only certain nm(red/blue) than hps even though they are substantially lower in total par.

But the fact is that any par light is quanta... and quanta =yield...to a point of saturation(which MJ has a much higher satuartion tolerance than other commonly indoor grown crops). Obviously better spectrums can do more with less, but only so much. If you look at the actual photosynthetic response for chlorophyll a,b, even green and yellow photosynthesize...and still pretty good too(over 60%), just not as quickly/efficiently as the better ideal nm's(~90%).

Back not too long ago led's had to rely on efficiency in spectrum to make up for the actual lack of light photons(energy for the plants)...well now led's have flipped the tables and even using plain all whites with no super specific growth spectrum design, watt for watt against hps will outperform. or equal for less watts.
 

CaliJoe

Member
Obviously better spectrums can do more with less, but only so much. If you look at the actual photosynthetic response for chlorophyll a,b, even green and yellow photosynthesize...and still pretty good too(over 60%), just not as quickly/efficiently as the better ideal nm's(~90%).
I agree with most of your statement, but the part above I disagree with. Green and yellow light is almost useless to chlorophyll (as the first chart shows) and yellow light is not very useful overall for photosynthesis. I don't believe it comes close to reaching the 60% mark, more like 10%, and what spectrum does most MH and HPS lights put out.... yellow, which to me is a lot of wasted energy. Cyan is a useful color as is the the lower green spectrum, but as you move up in green spectrum and enter the yellows it becomes less useful.



 

lax123

Well-Known Member
thx calijoe.
What I dont understand: the brightest area in those pictures -Picture "lens" is spot on the sensor, picture "no lense" its in the middle of the device and not on the sensor.
Why? Did maybe ur flashlight influence the measurements?

Could u also tell me: in which height above were the leds, in which angle to the middle of the leds and which power do they have. That would be great.
 

tags420

Well-Known Member
I agree with most of your statement, but the part above I disagree with. Green and yellow light is almost useless to chlorophyll (as the first chart shows) and yellow light is not very useful overall for photosynthesis. I don't believe it comes close to reaching the 60% mark, more like 10%, and what spectrum does most MH and HPS lights put out.... yellow, which to me is a lot of wasted energy. Cyan is a useful color as is the the lower green spectrum, but as you move up in green spectrum and enter the yellows it becomes less useful.



Response and absorption are different. Stardust schooled me on that
images.jpeg
Unknown.jpeg

And that is why hps, though not ideal, still produces great growth. But led's can and are doing better already.
 

JMD

Well-Known Member
This is what I come back too as well^^^ Quite the conundrum;-).........................the reality is that Lumens(per watt) DO matter.
Lumen doesn't matter - lumen is a way to quantify in relation how well the human eye sees it. Lumen and PAR is like oil and water.. both are liquids, but they are miles from each other.
 

CaliJoe

Member
thx calijoe.
What I dont understand: the brightest area in those pictures -Picture "lens" is spot on the sensor, picture "no lense" its in the middle of the device and not on the sensor.
Why? Did maybe ur flashlight influence the measurements?

Could u also tell me: in which height above were the leds, in which angle to the middle of the leds and which power do they have. That would be great.
Both pictures taken with the same camera phone with flash on to show the meter/reading. Red/Blue LEDs are notorious for taking bad pictures under so using the flash was required, but did not change the PAR reading. Holding the meter at a slight angle is why one picture you see the flash and the other you don't, but as you can see the sensor is within 1" of each other in both pictures. They all run at 700mA and were mounted 12" above the plants.
 
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