LED angle and light burn

[invi]

Hey!


Was wondering if anyone had some experience with different LED angles - which angle allows for about how much distance between canopy and the lights - using 3W LEDs? Is it possible to get light burn with 90 and higher?

Will a single 3W LED cause light burn, or does it matter a lot how dense the LEDs are packed on the panel?

I'd be curious about 60, 90, 120 and higher angles - any info would be appreciated!

cheers

 

[Hosebomber]

It is possible to bleach your plants/buds with any angle. It is simply the plants response to an over saturation of light. If placed close enough, yes a single diode can cause this. The density of the LEDs on a panel will effect a few things. First the heat from those LEDs needs to be dealt with to avoid overheating the diode. Overheating can cause to early failure, spectral output change and thermal runaway. Secondly, it increases the number of photons in a given area. The more photons means more light for the plant to use. The third is the disparate heat. even if you avoid the problems from the first issue, you will still have to deal with the increased heat in your room. Granted it will not be nearly as much as an HID system but it will still be there.

The angle used on each diode is done for a number of things. To increase the footprint of the panel, increase the penetration of the panel, and provide a better spectral blend over a given area. There aren't many LED manufactured that have a greater viewing angle than 120 degrees so I won't go in to that. Going below 60 degrees would require a very narrow set of parameters that I personally cannot see being viable for plant growth with my current knowledge.

Hope that answered all of your questions.

 

[invi]

Anyone cares to elaborate on actual distance?

Thanks for the info anyway.

 

[Hosebomber]

There are a lot of variables that go into the distance, not just the angle of the lenses. Type of LED, current being driven at, brand, bin, model, stage of growth the plant is in, height of the plant, temp in the grow room. It's practically impossible to give an exact answer on this without being there and monitoring the grow.

 

[HighWaterMark]

I have a pressing interest in this question. I was told that burning (or bleaching may have been the term) was more ofter caused by a proximity that didn't allow the spectra to blend, so that you were getting a preponderance of a particular LED wavelength spotting different areas of your canopy.

In the same conversation I was told of something someone was marketing that they termed a parabolic reflector (?) that allowed the spectra to come off the panel blended and hence the panel could be placed closer to the canopy as long as heat considerations were maintained.

Anyone familiar? I'm shopping.

 

[invi]

There are a lot of variables that go into the distance, not just the angle of the lenses. Type of LED, current being driven at, brand, bin, model, stage of growth the plant is in, height of the plant, temp in the grow room. It's practically impossible to give an exact answer on this without being there and monitoring the grow.

There will be 46 3W and 3 10W US or EU LEDs (not picked brand, only wavelengths yet) - all driven at recommended current. Plants in question are in flower and their height was one of the things i wanted to figure out (what grow style the lamp would be able to support in other words, and how much penetration is lost for the bleach distance).
I'm also thinking of using higher angles for wavelengths that are represented by a few leds only to have a more homogeneous spectrum, and was wondering if its worth to shape the panel so that these would be closer to the canopy - in case difference in bleach distance is huge.

 

[Hosebomber]

Highwatermark, I have seen the new Sol LEDs and I can assure you that they are not using a parabolic reflector. A parabola collects all incoming waves and points the to the focus. The focus is a single point and which all waves (be it light, microwave, radiation, sound, etc.) that hit the reflector are focused to. This is used in large satellite dishes to receive a signal and radio telescopes. It can also to the exact opposite as well, use a point source at the focus and send out waves in a perfect mirror of the reflector. This means that all photons leaving the reflector come off at exactly 90 degrees. Straight down toward the plant in this case. As for the bleaching being caused by not having a good spectral blend, that is kind of a half truth. It is from photon saturation. Meaning that the photo receptors in that portion of the plant have used collected too many photos (regardless of the spectrum) and have lost their ability to collect more light. Over time they can repair themselves and start functioning again. The bleaching can be caused by a single wavelength or white light, it makes no difference.

Invi, first I wouldn't suggest running the LEDs and their listed current. That current is done under ideal conditions with the Tj being 25 degrees C. It is not likely that you will be able to maintain that junction temperature for very long under normal operating conditions. Secondly, If you are using 3 watt LEDs I would suggest at least 12 inches from the canopy. If you add lenses, then you need to increase that height. How much you increase the height depends on all of those factors I listed before. With the 10 watt diodes, I would suggest having the panel at least 18 inches from the plant. I'm assuming you are designing it similarly to the Advanced XML panel?

 

[LovingGreeen]

Hi,, I've had no problems with burns from LED's so for. I have put mirrors up to help too even,,

 

[invi]

Thanks for the info!

I havent seen this XML design yet, but looks nice - i was planning to make a smaller panel that is easy to scale like one block in the XML. I wanted to use the 10Ws mainly to give overall spectrum coverage and because their peak wavelength is configurable.
Also was surprised how close Hans (bonsai hero) got with the 100 degree angle leds to the plants - was thinking of using 120 deg 10Wers, but not if i still have to keep the 12 inches. At first i thought he uses 3Ws as well.

I'm thinking of using 60-90 for reds, 120 or 90 for blues and 120 or 150 for wide band if available. Not quite sure how to figure this out with least possible amount of experimenting.

Probably cree leds.

 

[HighWaterMark]

Highwatermark, I have seen the new Sol LEDs and I can assure you that they are not using a parabolic reflector . . . As for the bleaching being caused by not having a good spectral blend, that is kind of a half truth. It is from photon saturation. Meaning that the photo receptors in that portion of the plant have used collected too many photos (regardless of the spectrum) and have lost their ability to collect more light. Over time they can repair themselves and start functioning again. The bleaching can be caused by a single wavelength or white light, it makes no difference.

Hosebomber,

Thanks much for the detailed reply. You have answered my question. I apologize for not responding inside of three days. I've been away from modern technology (yea for me). Again, thanks a million.

Oh, 'quick question re same company. I've been reading up on the EXTREME Series. In your opinion is there anything to the X2 lens' intensity/penetration or is it, shall we say, a bit more hyperbole?

-HWM

 

[Hosebomber]

I'm just gonna cut to the chase, stay away from that company. Yes, I know people have grown with their product and gotten ok results. It simply isn't worth the risk that the owner would do the things he/she has previously done. There are a number of other companies out there that make a product just as good for the same price or cheaper.

 

[HighWaterMark]

Thank you for being direct.

 

[HighWaterMark]

Horsebomber,

My research has come up with the following four complaints from a consumer advocacy website. They are listed below in order of reporting:
1) Ripoff Report | Quantum LED Ltd. | Complaint Review: 911352
2) Ripoff Report | Hydro Grow | Complaint Review: 954054
3) Ripoff Report | hydro grow led | led grow lights | Complaint Review: 955817
4) Ripoff Report | hydro grow, HGL Technologies | Complaint Review: 956158

If the info therein corresponds to what you've heard around the campfire, I'd appreciate being told that.

I like to support our sponsors. If there's an American LED company that both advertises with 420Magazine and generates greater yield and enhanced quality when compared to other LED companies that you know of, I'd love to be made aware of that as well.

Thanks for your time which I realize is valuable.

Take Care,
HighWaterMark

 

[Smokemupm8]

Hey Invi, How you doing mate??
Thought id better drop in and say HI... HI!!! just reading your question about LED's Im lost when it comes to them, but Id figure they may be like CFL's, unless they emit more heat. If they do you always want a bit of space between tops and globes.
I didnt read wot you wrote about angles, but what I was gunna suggest if you need to reflect light. Buy some MYLAR and cut it o size of each panel and you can sticky tape them to the panel so they also help direct light into a ceratin area like a reflector - but cheaper
SORRY IF THAT HAS NO BEARING ON WHAT YOU WERE MEANING!! LOL.. Too lazy when im baked?
But yeah were you using a MH or HPS before? My MH is near stuffed, time for a new one I think!
Take it easy hope you get it all sorted buddy, later mate. Smokemup

 

[CaneyeBus]

Hello Horsebomber,

Ive read quite a few journals (Steveh, Maers, Omm, Munki) using Leds and i've seen your experience and knowledge on the subject.
First off THANK YOU for such detailed info and knowledge on this technology in regards to our beloved plant. I have a question about a certain LED company/manufacturer that isn't a 420 sponsor and i would like your opinion of them and their product.Namely the 400w.Led they offer. I have link to to a interview the owner of the company did. He did reveal a lot of info on the product. I would just like to know the vibe you get from what you read. I have also asked SteveH (in a pm ....not sure he will respond as i am somewhat a noob as far as posting is concerned and i like to read more and see if any of my questions have already been answered)

Any feed back will be much appreciated.

 

[CaneyeBus]

ah Just read another post where it ays its okay to say the name of the company/manufacturer. Just not to post a link. Got it.
Horsebomber, The company is California lightworks and the Led i am referring to is the solarstorm 400w. "george" int he interview says they use the 120 angle lens providing for a much better footprint and coverage. I do have the link to the interview if you dont mind take a gander, I will pm you.

Thanks, Caneye

 

[Hosebomber]

It appears that they have changed their design a great deal since I tested them out. They used to use 3 watt diodes and have a little different spectrum. He is correct on the 120 degree lenses, anytime you increase the angle that light goes out it increases the foot print. Then the issue becomes how much penetration do you have? I have not tested 5 watt LED as I personally haven't seen the need for them. I'm also not very sure about their use of tube fluorescent bulbs to get UV: B. I'm not 100% sure they produce enough light at their suggested height to penetrate into the canopy. It is a cleaver idea and makes sense tho. Other than that, the only thing I don't like is the fact that they name their produce deceptively. Number of diodes times named wattage of the LED is deceiving. At least they tell you that it only pulls 650 watts max. I would love to see the interview if you want to PM me the link.

 

[CaneyeBus]

Thanks Hosebomber, PM sent.