Defying The Inverse Square Law

New champion on the block!

This morning I remembered that I have some spare bulbs on stock for the light above my kitchen island, I found them, a 6 pack that I bought one your ago, not sure where but I suspect it was at Costco.

This bulb is a completely different build with only 6 diodes in it (the other bulb had 15 diodes) and although the lenses in front look similar, on the inside they are very different.

Also, this new bulb is of much more quality when it comes to heat dispersion. If I have time enough I will try to do a side-by-side comparison. I have the feeling we (perhaps I should say “I”) know only the top of the iceberg when it comes to bulbs like this.
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Note, this is still a small bulb/spot with a diameter of 61 mm or 2.5”, just mention it as it looks like a big spot on the picture.
 
Here is the break-down of the last 2 bulbs.
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I’ve been playing around with some cones but did not come up with something better until now.

Fi 1.
The cone consists of two parts, a nurserey pot with a hole in the bottom which is slightly smaller than the bulb, when put over the bulb, the bulb is about 10 mm into the nursery pot. I have extended the nursery pot with a part of a yogurt container and lined the cone with high reflective mirror film. This is how I did my last test with the outcome of 3000 LUX.

Fig 2.
HOWEVER, if I take the cone off and hold it around 10 – 15 mm UNDER the bulb, I get readings between 4200 and 5100 LUX….. It fluctuates because I can’t hold the cone very still with one hand while looking at the readout in my other hand.
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So the shape of the cone is another crucial factor, basically I knew that but 30 – 60% increase with just holding the same (simple) cone just a bit lower was still a surprise.

When I started this post, I thought I would end up with a few car headlights on the ceiling with LEDs in them, I was working towards that (almost bought headlights lol) but now I am not so sure any more. If I find a better and easy to make cone, I am not so sure if headlights could beat the results I would be getting, certainly not price-wise.
 
bluenoserjoe said:
Curious to know if this just blocks the upward light or actually redirects it thus intensifying the resulting beam. It redirects heat very well so I would think the same for light. My seedlings sure love it. :peace: :ganjamon:
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If it "redirects" heat very well, just like you'd expect it to do with any wave energy (light, heat, even sound) then doesn't that defeats the purpose of this whole experiment? I mean, if one wanted to increase the intensity of the light they are using, they can just bring it closer to the plants (remember inverse sqare law lol) but that's not always feasable due to the heat.. but if building deflectors/concentrators can concentrate the light at a further distance and does the same with the heat given off.. then what's the point? I feel bulb manufacturers would've thought of this by now.
 
rippedcb said:
building deflectors/concentrators can concentrate the light at a further distance and does the same with the heat given off.. then what's the point?
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A deflector like mine creates only a bit of radiation close to the bulb, my plastic cone does not get hot. And that's the whole point, create a bandwidth of good grow light further away without the heat.
 
Budsbunny said:
A deflector like mine creates only a bit of radiation close to the bulb, my plastic cone does not get hot. And that's the whole point, create a bandwidth of good grow light further away without the heat.
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Your plastic cone isn't getting hot because your deflector is deflecting the HEAT along with LIGHT further away... defeating the purpose of what you are trying to achieve. Good luck..
 
Pbass said:
I could have gone this route, in stock at HD but I'm much further ahead, I know you'll agree!
feit-electric-grow-light-kits-glp24fs-19w-led-64_1000.jpg


Feit Electric 2 ft. 2-Light 19-Watt White Full Spectrum LED Non-Dimmable Indoor Linkable Plant Grow Light Fixture, Daylight - $39.97
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Don’t knock em, till you try them. Lol!
They work great for small areas. Now that I’ve moved them into my 5x5 tent, I use them to fill the dead spots and for natural light. (I run blurples)

First time using it to veg some plants that never endedup getting picked up. Lol!
(Abandoned ladies grow)
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Used them again while waiting for the Abandoned ladies to finish off.
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rippedcb said:
Your plastic cone isn't getting hot because your deflector is deflecting the HEAT along with LIGHT further away... defeating the purpose of what you are trying to achieve. Good luck..
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I've measured the temperatures as well, just did not mention them because it is almost neglect able. Most "heat" is taken by the heat sink in the bulbs, but thank you for your good wishes.
 
bluenoserjoe said:
????? Are the diodes themselves designed to reflect light in any particular way. ie. a ninety degree cone for instance? Or is all light direction totally controlled by reflectors?
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The diodes just gives light to the front and side and can be redirected in many ways. Below are 3 basic ways, the one on the left without anything, in the middle with a concentrator inside the bulb and on the right (the one I use) has a concentrator/lens in front of the bulb. And then there are a ZILLION combinations possible.
feb18_0.jpg
 
I hooked up this cone in the position of the picture but my camera was empty to take a picture…. The reading was 4400 LUX, which is good, but there started to be a kind of hot spot in the pattern so I that is not going to fly.
The yellow visualization was done with PowerPoint and does not look exactly like this, just to give you an impression of what I mean. I think I will do another Inverse Square Law test, now with these bulbs and cone to see the difference with the previous 2 tests but I will have to make the cones first.
feb18.jpg


The cone shape I use is not a concentrator or lens, it only directs the light that goes more to the side, more downwards, but still providing a smooth overflow intensity to the outside.
 
February 18, 2020

This little clone and seedling went under the new (household bulb) lights 10 days ago and they are doing fine. Roots start to come under the black nursery pot, a few days more and they will go into the new bubbleponic system with new led household bulbs.
I will defoliate the clone at the bottom a bit.
IMG_7747.JPG

feb18_1.jpg

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Feeding is done by a wick (mason cord)
Nutrients: tap water (500 ppm) + 150 ppm Masterblend (mix 10 - 8 - 5)
Ph. 5.6
Soil: Coco Coir 80% + Perlite 20% + Hydroton on top.
 
February 18, 2020

I have finished the last test and tried to put 3 tests in some numbers, if it is not clear for you, don’t hesitate to ask.

Test 1
This is the first test I’ve done with 9 household bulbs (7W) without the diffuser.
test1.jpg


Test 2
Same as test 1 but with cones attached to redirect some “lost” side-light downwards.
test2.jpg


Test 3
5 LED spots (7W) with a longer cone, only 5 spots as I did not have more.
test3.jpg


Below you see the drawing with the different distances of the test, projected on an image of the Inverse Square Law. You could compare the results of the tests with the %’s in this picture and you will see that the results of the tests are MUCH higher. (basically double)
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OUTPUT DENSITY (LUX) PER DISTANCE
The results of test 3 stay a bit behind, but there are only 5 bulbs and 5 is actually not a good number to divide as a light pattern but so be it.

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LUX OUTPUT PER WATT
This results speak for itself, the 5 spots with the longer cone have no real competition when it comes to low energy usage while giving more light than the rest.
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One remark for now, spots with the longer cones should not be used on the short distance C as they don't give enough spread pattern.
That's it for now, I will answer questions but am not going to post anything else the coming days, need to do my taxes LOL.
 
I am giving myself a 2 hours break today from doing taxes and a part of that time I will use to give you my thoughts on these lights and the testing and what would be my choice and why.

Lights
These kind of bulbs work –period-. I’ve been testing on cannabis and others for almost 2 weeks now and I notice good progress. Better than professional panels? Probably not, but I cannot really compare so I will give the latter the benefit, also because I use Masterblend, maybe with other nutrients my results would be much better.

It is easy to manipulate the spectrum by exchanging bulbs with different color temperature, I am very flexible with being able to do that.

I have used 9 watt bulbs but when it comes to intensity I think 12 watt bulbs would be a better choice. On the other hand, 12 watt bulbs are much more expensive to buy and with the 9 watt bulbs, for the same or less money you can add a few more and have a better spread on the canopy.

Testing

Believe it or not, but my choice will be the household bulbs with the small cone. The cones I made all work differently at each distance. I did an extra test on 45 cm distance and these bulbs did very well (see graph second from the right) and the results of the spots with the large cones plummeted. (long cone, 5 lights, bad spread)
test-results.jpg


Another reason for choosing these bulbs is the pattern on the canopy. 9 bulbs, compared to only 5, give an excellent and even spread on the canopy, maybe even an overkill.

The nine bulbs use more wattage but on the other hand you could do with less. I mean, if the closet was twice as wide I could use only 12 bulbs but grow 2 plants in the chest (which is what I will do in the dresser), that would give a much lower wattage per plant still having a good spread on the canopy.

The cone

These little cones work very well, they pretty much double the output intensity. These are just cheap nursery pots (10 cents or so) and easy to make, you only need a box cutter knife and some tape. I used a quality mirror film on the inside, if you use duct tape or so you will not get the same output, I’ve tested several materials but nothing comes close.

Another nice feature of these cones is, that you can “aim” them to a certain extend.
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Well, I hope this was of any value for you, it certainly was for me and I can hardly wait to put some girls under these lights….
 
With playing around with different cones to measure intensity I started to get the feeling that, next to different inside liners, the shape of the cone has a big influence on the outcome at a certain distance so I will take some time today to test a “scrappy” few with different inside liners and make a good one after some results. Testing will be done at 45 cm, this was the distance of the last, extra test. The panel will be height-adjustable, and I know I can always keep it at that distance when the plants grow.
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Budsbunny said:
With playing around with different cones to measure intensity I started to get the feeling that, next to different inside liners, the shape of the cone has a big influence on the outcome at a certain distance so I will take some time today to test a “scrappy” few with different inside liners and make a good one after some results. Testing will be done at 45 cm, this was the distance of the last, extra test. The panel will be height-adjustable, and I know I can always keep it at that distance when the plants grow.
IMG_7854.JPG
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:peace: :ganjamon: This is why I had earlier asked about the light direction emitted by diodes. If given a known angle off the diode then simple math could plot the cone angles needed to concentrate the light at a given distance.
 
bluenoserjoe said:
:peace: :ganjamon: This is why I had earlier asked about the light direction emitted by diodes. If given a known angle off the diode then simple math could plot the cone angles needed to concentrate the light at a given distance.
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I don't know the angle off the diode, do you?
 
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