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Food for thought

fwril

fwril

New member
So I have been doing some brain storming on LED lights. There are a million options some cheap some not. The issue is there is no real way to gauge them. A 600w led light will actually only pull 180-260 watts from my experience and there is far more variation than that on the market.
So I was trying to come up with a way to compare a LED light to other lights since lux or lumens are not accurate due to the multiple spectrums of light they emit.
My thought was to take a black cloth at a set distance from the light and measure the temperature difference of the cloth to the ambient temperature around it. Black being able to absorb all visible spectrums of light would he the best was to see how much light is being put out by the light. And by measuring the difference you could compare to other lights even if the traditional lights make more heat.
I think LED may be by far the most efficient lights when it comes to converting power to light. The issue is people bare compareing a (600w) Led which is only 200 draw to a 600w traditional light. If you had 600w or 3 led lights I think you would come out ahead on light output.

Anyone willing to test this with me? I have leds but no traditional lights.
 
That's an interesting idea. One thought that comes immediately to mind is that the "black" cloth will probably have different absorbance/reflectivity at different colors (the "black" color may be from a mix of three dyes and not truly "black." Another thought is the difficulty of getting good temperature measurements.

There are light meters ("PAR meters") that will work accurately with LED lights, but they are still pretty expensive. I expect that cost will come down soon when some smart Chinese manufacturing company sees that they can make a meter that sells for $300 today and sell it at a profit at $99. Such seems to be the way of things.
 
Like doctor said. You need a PAR meter which measures light emitted regardless of the spectrum (inside photosynthetic range) the units to compare are called micro moles of light. The cloth idea is good but I think other variables may render the experiment inconclusive
 
Not Sure was just looking for a cheap way to test my theroy. I personally fell you can get more bang for the buck as far as power cost with multiple small LEDs vrs one large hps or mh light.
 
I run 3 viper spectrum 450s in some tents. 1000 watt hps in others. 2 Viperspectrum 450s in some. 1 450 viperspectrum in 1. I can do do it with all. But so far good luck on that.
 
Umm- just use the PAR charts that come with the LED's- If they don't bother to test them- don't bother to buy one!
Here is one for the Mars Reflectore96 (480w)

detail-5-96-high-par-Mars-Reflector-480W-Led-Grow-Light-Hydroponic-Indoor-Plant-Veg-Flower-Ful...jpg


It will also give you coverage area.
I don' trust independent tests- as some buy the rejected ones - not ones sold by the manufacturer.
 
The best value light technology is gas discharge, commercial horticulture companies know this and is the main reason why most commercial indoor facilities are still gas discharge. LED technology is still some time away from being able to regenerate investments over rational timeframes. LED products such as california lightworks, spectrum king, fluence, nextlight, and black dog that provide comparable performance to sodium discharge, require a substantial investment that take years to recover the initial costs.

Evetually LED will superseed all lighting solutions but that time is still a few years or more away. I will myself, knowing lighting technology and plant science. Will continue using gas discharge, until LED has reached a stage of practical and economical value.

Photon density plots can be tricky and inconsistant, there is no protocol through which manufacturers must abide. So there are many ways which manufacturers can use to manipulate the results. Such as coverage area, sample points, sample numbers, reflections etc. I generally suggest to avoid them due to these variables, however they may still provide useful information if correctly interpreted. The only reliable way to ascertain data on the true capability of a fixture, is photon flux or PPF. There is no reason manufacturers cannot provide this, unless they choose not to because of revealing deficienies in their products. High quality products such as the ones i have previously stated, confidently provide this information because their fixtures are of high quality and can provide performance characteristics comparable or better than gas discharge.

If you want to obtain a cheap solution to measure flux density, you can purchase quantum sensors from major manufacturers such as apogee and connect them to a simple multimeter which through basic multiplication, provides photon density values.

Have a look at my articles or ask any questions you may have.
 
I use 4 70w hps area lamps in a 2.5' x 5' space. I get great coverage & excellent penetration. Because heat is virtually a non-factor, I can keep them within 6" of the canopy. No hot spots.
 
This is a great advantage, spreading the light like you do has so many benefits. Light uniformity, heat distribution, photosynthetic efficiency. Must be nice :)
 
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