I would still like to see some specs......How big are they? Whats the coverage and penetration range?
I am one who believes that light intensity is a huge factor in achieving fat, plump buds. I can't see me buying 9 150 wtt LEDs and expect them to do what 9 300 wtts can.
The problem (and I'll be pretty much duplicating this post in a different thread about LEDs), is this: Luminous intensity is relative to the human eye. In fact, it's relative to the wavelength that the human eye is most sensitive to -- 555nm (what we would refer to as pure green).
Humans tend to want to equate the intensity we see to the intensity the plant "sees" -- but this is simply not the case. So a comparison dealing strictly in luminous intensity is faulted -- namely by the fact that the human eye is most evolved to sense a spectrum not emitted by any but the white broad-spectrum LEDs in these lamps. Interestingly enough, plants are the opposite. The light that appears the "brightest" to us (555nm pure green) appears the "dimmest" to them, and vice versa. The light that appears the "dimmest" to us (near-UV, 380nm and far red, ~700nm) appears the "brightest" to them. Well, ok, not exactly, but close. Since peak photosynthetic production occurs at around 660nm for Chlorophyll-A, and around 455nm for Chlorophyll-B, it follows that these are the wavelengths that plants are most sensitive to, or "see" as the "brightest." It is simply difficult for us to visually comprehend, as our human eyes are not tuned the same way.
A more accurate comparison would be to test the percentage of spectrum-specific output from the HID bulb, and then compare the percentage to the LEDs. This is more realistic, since only a small amount of the total luminous output is actually used by the plants (in the realm of 3-5%, at most 10%). So again, a 400W HPS light putting out 55,000 initial lumens is really only putting out around 5,500 lumens of USABLE light (~100% absorption), at a maximum. The rest of the light is just wasted energy. Compare this to the 3,360 lumens (~100% absorption) put out by the LED lamps referenced in this thread. Not bad when it is using half the energy, with no residual loss. This brings about the old adage, "Just because you can't see it, doesn't mean it's not there."
If you would like to take a look at the specs I have been provided with, there is a link to the supplier in
post #15 of this topic.
One thing I would like to say (and some of you already know this, if you've been paying attention), is that I am not an expert on LEDs. I am simply a person who does a lot of research, to try and achieve the best results possible. If anyone has any doubts, I invite you to speak with either a color scientist, or a horticultural scientist. My research and theories are just that, research and theories. When at some point I have the ability to test all of them, rest assured you will all be privy to the results. Now to get me one of those
OceanOptics Spectrometers...