LED strip reflector test

[PeteR_1]

Lenses and reflectors seem to be a very tricky science, almost an art to design it well. Fortunately the strip form factor makes it easier by ignoring one dimension, flattening it to 2D makes it easy to simulate it in that browser app and design something that is both easy to build / cheap to order and effective.

Crazy how your bulbs produced weird patterns, how wide was the beam pattern? My previous "setup" is just 4 GU10 36° spot lights in a row on the dining table, that results in a decent uniform bright line where I could place my seedlings and young plants. But extending this idea means: DIY with 230V, let's not do that in a wet area, and crappy lm/watt of 80.

I have no doubt though that a 4x4=16 lamp setup in a grid would do well enough for my goal of just growing peppers and herbs, 9600lm @ 2700K CRI90 ~= 160 umol/s @ 120W, maybe 120 umol/s net if you take out some for losses via sides. Not very power efficient though, these Samsung strips are clearly far better.

The E26 Bulb Beam angles varied from ~ 40° - 120° using PAR 38, BR30, etc.; with and without Lenses, modified A19/A21 Plastic Globes; ends removed, wrapped in foil tape... They definitely created adequate "Spot" Lighting at a specific distance, but was not adequately uniform as that distance decreased when plants grew up towards the light. BTW, the 12 - Bulb String light Fixture in a "Surround", 1600 Lm - 15 Watt LED bulbs with Globes removed (~ 21,000 Lm , 315 umol/s PPF, 180 Watts, 1.7 PPE) had ~ 40,000 Lux, 600 PPFD (umol/s/m2) min average coverage @ 1' (300mm) over a 2' (600mm) x 3' (900mm) footprint.

Grow Light Tests of E26 Base Bulbs, before joining this Forum

My early inspiration (thought I'm not a "Grower") for using E26 base LED bulbs was;

E26 Base LED Bulbs as Grow Lights... https://www.icmag.com/forum/marijuana-g ... st11687495

DLC Listed High Bay LED Fixture 5000K Lumiled LED @ 1.97 PPE.

22,000 Lm, 1.97 PPE, Measured 49,000 Lux, ~ 686 PPFD min average coverage @ 1' (300mm) over a 2' (600mm) x 2' (600mm) footprint.
Linear HighBay LED... https://greenlightdepot.com/collections ... 6442804267


My desired coverage area was ~ 2' x 9' (~ 3 - "Bun Pan" Fixtures) and LED Strips modeled after Linear High Bay fixtures provide much better uniform coverage... viewtopic.php?f=32&t=5872

Samsung F-Series Gen3 LED Strips 8 - F564B @ 240W & ~ 45,600 Lm or PPF 656 umol/s, 2.5 PPE (umol/J), Measured 74000 Lux ~ 1065 PPFD @ 1' (300mm)

[miles]

My desired coverage area was ~ 2' x 9' (~ 3 - "Bun Pan" Fixtures) and LED Strips modeled after Linear High Bay fixtures provide much better uniform coverage... viewtopic.php?f=32&t=5872

Samsung F-Series Gen3 LED Strips 8 - F564B @ 240W & ~ 45,600 Lm or PPF 656 umol/s, 2.5 PPE (umol/J), Measured 74000 Lux ~ 1065 PPFD @ 1' (300mm)

Whoa that's a lot of light. 8x F564B @ 30W each per module, and 3 of them in a 2x9' area? Intense...

How is the brightness at other distances, does it get hotter nearer or further away than 1' / 300mm? That's the main thing I want to fix, narrower spot = distance has less effect on brightness, I don't grow 1 single thing, all herbs are different sizes although I have 2 shelves with lights at different heights, it's still too variable.


Too bad the other experiments didn't work out. With the 34° spot lights here, I noticed that you have to cluster them tight to get even coverage, or the line goes hot-cold-hot-cold-hot-cold-hot. I wouldn't go narrower than 60° and make sure the circles overlap a lot, but then you're better off using array lenses and power led instead of main voltage. It certainly is a ton more work than just install more lights, 240W x3 @ 18ft2 = 40W/square feet which basically guarantees enough light no matter what.


My first install is just 25W in 4 square feet (80x50cm area but not full of plants), and 2x 25W on the other shelf. Hitting peak luminance of 20-30k lux is enough for me. That's 6.25 and 12.5 watt per square feet and running the modules hotter than you do (F562B @ 25W vs F564B @ 30W) - in hindsight, should have though of that and run more lights at lower current, LEDs are cheap.

~~

I haven't had the time yet to glue the reflector v2 together, I'm super curious what kind of light distribution / PAR map it will generate. I hope it is a bit more even, the side drop off even in a 40cm wide beam zone was bigger than I expected. I'm also looking at printing a sheet for on the ground to mark out distances to generate a light distribution diagram, angle vs light strength, and see how it differs from the original one.

[PeteR_1]

Whoa that's a lot of light. 8x F564B @ 30W each per module, and 3 of them in a 2x9' area? Intense...
How is the brightness at other distances, does it get hotter nearer or further away than 1' / 300mm? That's the main thing I want to fix, narrower spot = distance has less effect on brightness, I don't grow 1 single thing, all herbs are different sizes although I have 2 shelves with lights at different heights, it's still too variable.

There is little to no measured increase in ambient temperatures below, there is an increase of only a couple degrees at less than 6 inches (150mm) from the light.
The Fixtures are "Modular", LED Drivers are Dimmable which allows them to be adjusted to maintain the required light intensity (PPFD) and located remotely. They can also be easily wired in Parallel off a single Driver or any combination of larger or smaller capacity Drivers if required.

F564B Strip Build... viewtopic.php?f=32&t=5872
The "required" Grow Area and Stage of Growth for Light Size are;
"2 ft x 4 ft Area Supplemental Plant Grow Light
500 PPFD * 0.8 m2 (sq m) = 400 PPF (Fixture)...

Measured Lux / Calculated PPFD @ Center;
1512 umol/s/m2 @ 6 in (15 cm) - 105000 Lux
1065 umol/s/m2 @ 12 in (30 cm) - 74000 Lux
432 umol/s/m2 @ 24 in (60 cm) - 30000 Lux
252 umol/s/m2 @ 36 in (90 cm) - 17500 Lux"

Too bad the other experiments didn't work out. With the 34° spot lights here, I noticed that you have to cluster them tight to get even coverage, or the line goes hot-cold-hot-cold-hot-cold-hot. I wouldn't go narrower than 60° and make sure the circles overlap a lot, but then you're better off using array lenses and power led instead of main voltage. It certainly is a ton more work than just install more lights, 240W x3 @ 18ft2 = 40W/square feet which basically guarantees enough light no matter what.

Although the 12 - Bulb Outdoor String Light with 1600 Lm Dimmable LED bulbs only cost $40.00 complete it was evident that the Commercially available LED High Bay Fixtures would provide better coverage at higher intensity and efficacy at only $81.00 with a lot less labor. And could easily be dimmed / adjusted for light intensity (PPFD) with an added Dimmer Pot.

My first install is just 25W in 4 square feet (80x50cm area but not full of plants), and 2x 25W on the other shelf. Hitting peak luminance of 20-30k lux is enough for me. That's 6.25 and 12.5 watt per square feet and running the modules hotter than you do (F562B @ 25W vs F564B @ 30W) - in hindsight, should have though of that and run more lights at lower current, LEDs are cheap.
~~
I haven't had the time yet to glue the reflector v2 together, I'm super curious what kind of light distribution / PAR map it will generate. I hope it is a bit more even, the side drop off even in a 40cm wide beam zone was bigger than I expected. I'm also looking at printing a sheet for on the ground to mark out distances to generate a light distribution diagram, angle vs light strength, and see how it differs from the original one.

@TEKNIK and several other "experienced" forum members have advocated for increasing LED quantity to run "Soft", cooler with increased efficiency, it works! It can also reduce or eliminate the need for heat sinks, but stiffening is still required. I've purchased several inexpensive LED strips for trials, but have not invested much time in PAR Maps, the "Light Sizing calculations" tend to be very (extremely) close to measured values. Its also quick and simple to make and test working models with the Leverlock Connectors, Perforated Bun Pans and 12 Vdc - 54 Vdc, 75 Watt and 240 Watt Dimmable LED Drivers.


Test Build with Bridgelux Gen2 560mm Strips, BXEB-L0560Z-50E2000-C-B3... viewtopic.php?p=23538#p23538
"Drop off / decrease in light intensity from center to edge of ~ 300mm x 660mm footprint is less than ~ 500 Lux (~ 7.0 umol/m2/s, ~ 11%)
32 Watts; PPFD @ center
6" - 26000 Lux, 364 PPFD (umol/m2/s)
12" - 12,600 Lux, 176 PPFD (umol/m2/s)
24" - 4500 Lux, 63 PPFD (umol/m2/s)

Additional Measurements at 67 Watts (100%)
67 Watts; PPFD @ center
6" - 48000 Lux, 672 PPFD (umol/m2/s)
12" - 24500 Lux, 343 PPFD (umol/m2/s)
24" - 8700 Lux, 121 PPFD (umol/m2/s)"

[cmar]

Just some musings on the topic here,
When it comes down to it the test results are the test results and will tell you what's actually going on.
BUT
If you are using multiple strips, you should test with multiple strips.
Multiple strips will have overlap.

Also if you're growing in an enclosure you should test in that enclosure.
If you're growing in a large open area the reflector will help focus the light where you want it, but if you're going in an enclosure the walls basically act as your reflector and will reflect light into the side of the canopy.

Basically a single strip with and without a reflector is not representative of what multiple strips in an enclosure will do.

[TEKNIK]

Light travels until it hits something, when it hits something part of it is absorbed and the rest reflected. So yes you can increase the light to a certain area by using reflectors but keep in mind that light will be absorbed by the reflector. Its worth doing in certain situations but not in other situations. If you don't have reflective walls where you are growing then a reflector can help increase intensity where you want it.

Most grow in tents or rooms that have reflective walls, your situation maybe different so in your case a reflector can help.
Nothing wrong with using a reflector or optics, in most cases growers want wider beam angles for an even spread because it suits their grow environment.