[Scrappy-doo]

All different size plants from 1oz to 4oz a piece. Some went in very small others were established. Yielded just over 3 and 1/4 lbs in that space and that's just a first run not dialed whatsoever. I think I can hit 4+.

Everything is in the link in my sig.

[McKush]

Hey Scrappy - i read your thread last night. Wanted to see your use of the GB. You started at 2' on plants vegging under a different light and reported some lumen shock (light damage.) Then i think you raised the light to 3'. Are you still running that way? Any height diff in veg or flower?

Ive had some spotting on my plants in veg but im not sure it is light damage or not yet. Ive had plants from 2+ to 3 feet from the light. So far the damage has been confined to the lower and older fan leaves. New growth and tops seem ok.

[Scrappy-doo]

Yeah they vegged under t5/fluorescent and got shocked when I flipped so had to raise the light. Settled on 30" from canopy. I'm on hiatus from growing atm so I only have the one run with the greenbeams. Next time at flip I'll start them at 42" to be safe and let them stretch into the light. Sounds like yours are pretty comfortable with your setup if the new growth is healthy. Good luck I'll be looking forward to seeing how they turn out.

[timmur]

Hey milkyjoe, here's a nice room full of Greenbeams!

Abcann Medicinals

Looks like they are using them for veg.

[Dank Whisperer]

Interesting to see a GB thread since I was thinking about them in the future. I'm curious if anyone can take some reasonably accurate measurements of the interior of their unit? I bet I could make something more appropriate for my needs by modifying the panels of a Silver Sun parabolic to achieve the same shape.

Also, I think I see the beginning of a misconception forming around these reflectors and I'd like to dispel it if I may. [To be clear, this is not a criticism of the company, reflector, or any of it's owners and should not be taken as such.]

I think the term "uniform output" is being misconstrued by consumers. I'm willing to bet my life that the level uniformity in output that they claim is only achievable: 1) in a very small area @ just the right distance from the light, or 2) using their complete system w/ modeling included. That is why you need so many reflectors, because each one is only capable of producing the necessary uniformity/penetration within a small "footprint".

[Dank Whisperer]

[I'm not in on many threads yet, and trying to get to 50 posts legitly, so excuse my multiple posts.]
If you were to wear goggles allowing you see the way the light projected out, you wouldn't see some magic glowing orb, you'd see something similar to what you get from a Maglite. Imagine hanging a bunch of Maglites so that their beams produce an even coverage, and that's what Cycloptics has done on a large scale.

[Dank Whisperer]

This is why using them, you have to back them of off to 30"+ to avoid problems, while the same bulb in other reflectors has allowed growth a few inches away w/ no problem. I've seen the same thing after switching a 400 MH/HPS from my first homemade reflector to the OG (P.O.S., tell your friends), thinking their claims of adequately lighting a 4x4 were legit. It might cover 3x3 w/ 600wHPS on a good day.

[Dank Whisperer]

And the OG burned plants when it was 36" away when one of the reflector panels distorted by the suction from the adjacent exhaust port. Had to back it off several inches to be safe.

Well, it turns out with any parabolic, you have to mount it way up high to get it to spread, and from my experience I've come to the conclusion that they generally project an intense beam of light that, on its own, is rather awkward and mostly unusable. You have to know where the "sweet spot" is within the projected beam, and it is rather small with these things. Again, that is why they require so many individual fixtures.

[Dank Whisperer]

In the end, it is just another parabolic reflector (been around since ~350 BCE) -- albeit a very well designed one. It was designed to be a constant variable in their computer model (1 fixture, for 1 bulb, @ a set height, spaced @ an even interval), not to be the end-all-be-all in small-op grow light design.

The vast majority of sales of fixtures are large scale growers with many of them having greenhouses. Magnum XXXXXXXXXXL-types are right out because they would block too much sun. Also, commercial growers don't mind shelling out the extra $ on ballasts and fixtures to achieve even light w/ minimal interference w/ the sun.

[Dank Whisperer]

If you have a larger operation where you plan to buy several fixtures anyway, then Greenbeams should definitely be considered. Smaller or irregular areas though, might be better suited with different reflectors. Something like a tent/enclosure would be an exception since the walls are reflective and very close, yet it's temp can be controlled.

Always use the right tool for the job. That means use the reflector that projects light in the "footprint" of your grow space; and more importantly, one that produces the proper intensity within that "footprint" at the canopy level, and not the ground.

So, to surmise:
I am not shitting on Scrappy-doo or McKush, as I am also a prospective Greenbeams customer. I am simply informing folks that the physics at work is a little different than the image they have conjured up when read how Cycloptics markets their uniformity levels. Don't get caught up in the hype, even if the hype is mostly true.