Are reflectors really worth the trouble?

[bvolt]

Hey guys,

For about the past year, I've been on a mission: find out all I can about LEDs and how they are used, not only by other gardeners, but by... interior designers and civil engineers... photographers and electricians... these are ultra-regulated industries, where reputations based on adherence to standards, transparency with testing results and quantification of every claimed specification is possible.

Kindly check out this video if you'd like to see someone build and test a 4000 LED, strip-light @ 1000w.

The thing I found amazing about this video, was that: once he turned on the LEDs, he only had a single lamp capable of penetrating the dense curtain of light blanketing the wall.

It was the 13w flashlight with the reflector.

[Ted]

Hey guys,

For about the past year, I've been on a mission: find out all I can about LEDs and how they are used, not only by other gardeners, but by... interior designers and civil engineers... photographers and electricians... these are ultra-regulated industries, where reputations based on adherence to standards, transparency with testing results and quantification of every claimed specification is possible.

Kindly check out this video if you'd like to see someone build and test a 4000 LED, strip-light @ 1000w.

The thing I found amazing about this video, was that: once he turned on the LEDs, he only had a single lamp capable of penetrating the dense curtain of light blanketing the wall.

It was the 13w flashlight with the reflector.

First off, loved the video. Definitely embodies the LG spirit. For reflectors, i think it would depend on your setup. In a tent, the sides are essentially reflectors. Those in open spaces it definitely makes sense.

[majorana]

I think a part of the question is what the lights are used for.

A reflector, as the video shows, can be effective in concentrating light in a particular area, which would be great for a flashlight. The reflective walls of a grow tent probably have a similar effect, but given the damned inverse-square law that's probably only marginal. My next grow will probably include some side lighting as well.

In the context of a grow tent, and given that with LEDs (and especially soft-driven mid-power LEDs) you can get very close to the canopy I think the discussion isn't about narrowing the beam but actually making sure you get an even, uniform spread.

I'm yet to build my LED-strip contraption, but my plan is to stick them all on U-shaped aluminum profiles. I guess I can stick half in the valley of the U (which would be, effectively, a reflector shape) and half "outside" of it (no reflector)and see if there's a noticeable difference.

On a side note, I was surprised to see that there's no heat-sink of any sort on the 1000W panel

[hideouspenguinboy]

http://www.rollitup.org/t/lens-and-refl ... ob.893660/

This is a good thread with tests using reflectors and not, showing the light spread in and out of a tent. Good data to show that in a tent, the tent is the reflector. (:

[bvolt]

Hey all,

So, let’s just get this out of the way... great responses, I don’t nessessarily agree or disagree with them, but that wasn’t the real point of the original post...

Incidentally... my position on reflectors is: if your light’s components are such that using a reflector is necessary, then I think you should use one (a look at my current setup will tell you as much - no reflectors).

IMG_4881.JPG (8.46 MiB) Viewed 1355 times

But since we’re there... is the consensus that the walls of the tent are as effective as secondary optics for putting light on the canopy? I’m not so sure...



The light reflected off the walls had to land there then be reflected down to the canopy.

If my optics bypassed the upper wall and sent the light directly to the canopy, wouldn’t that be putting more photons on the canopy?

Think of photons as paint.

If I have to use the “paint” on the upper wall to render this picture, that leaves less for coloring the canopy, no?

[oozing]

This has nothing to do with reflectors but if I found a way to mount everything upside down like that, would the plant grow down into light? Would it u-turn back into the substrate? I guess a seed would try to pop out of the bottom of the pot.. or never in the case of fabric pots.

[bvolt]

This has nothing to do with reflectors but if I found a way to mount everything upside down like that, would the plant grow down into light? Would it u-turn back into the substrate? I guess a seed would try to pop out of the bottom of the pot.. or never in the case of fabric pots.

It's funny you should mention this... cannabis is phototropic.

You may have proven this unintentionally without even realizing it...

Ever set your pot down on an uneven surface?

Phototrope.png (25.85 KiB) Viewed 1355 times

This is the concept behind vertical farming.

Roots, if you were wondering, will follow water where ever it goes, they don't give a f'ck if there's concrete in the way.

[majorana]

I have a couple of upside down pots I keep a couple of plants growing from: I'm pretty sure you can grow marijuana that way too. (Given that my upside down plants get sunlight, after about dropping for approximately a foot the leaves start curling upwards.) I wonder if there might the tiniest bit of advantage in such a growing technique? It would be very easy to try with a smartpot (i.e., fabric.) Who knows, maybe I should give it a try?

[majorana]

The idea still tickles me, but it sleeping on it I realized it definitely require serious water-proofing for the LEDs (places beneath the pots...). That alone pushes it to be next-year's project -- there are enough experimental improvements lined up for this coming spring

[Daisy Van Donk]

I wonder how the geotropic roots would respond? I suppose stem and roots would grow in the same direction? Please can someone do this...