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Originally Posted by BarraCuda™
Dont take my word for it. Ask the manufacturer for the lux rating. See if that particular light fixture is made for spot lumination.
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I have various manufacturers data I have already asked them for. I have been posting manufacturer supported data for most of this thread.
Further and for your information lux is measured in lumens per square metre. If the beam is concentrated on a small area. Then the lux will be very high, this is how lux is measured. Focussed spot lights have a high lux rating.
Quote:
Originally Posted by BarraCuda™
I agree with that. So you will need alot of narrow beam LEDs to luminate the entire tank right?
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High lumens LEDs are highly focused and not suitable for lighting wide areas.
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These statements are mutually contradictory.
You need multiple led’s (something we have been saying from the beginning) due to each having a low total lumen output. If you have a large number of them to get the high lumen total you also have proportionally high coverage.
Quote:
Originally Posted by BarraCuda™
Basic DC electrical theory tells you that Power(watt) = Voltage x Amperes
Assuming constant current, a higher voltage will give you higher wattage and a brighter bulb!
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These are not high voltage devices. Luxon’s LED’s are 4.5 volt (max).
Scaled up from your suggested 55, that would give 82.5 lumens not 135. Technology moves on!
Quote:
Originally Posted by BarraCuda™
CRI only tells you the difference between the colors viewed under sunlight and under the bulb. If the CRI is 100 then the color you look under the bulb will be 100% the same as you would have under the sun.
CRI = Color Rendering Index, nothing to do with spectrum quality needed for plants.
http://en.wikipedia.org/wiki/Color_rendering_index
What you should be looking at is Photosynthetically Usable Radiation (PUR) Plants typically require a peak at spectrum ~620-700nm for photosynthesis and other wavelength of light to survive. |
CRI is the ability of a device to accutately render an object within the visible colour spectrum (as supplied by the sun); typically between 400 and 700nm.
http://www.topbulb.com/find/cri.asp
This includes the photosynthetic action spectrum for most green plants (which also use the sun), so if something has a CRI of 100% (or near it) it will naturally cover the action spectrum of plants.
[This is what I specifically questioned when I asked about the missing 80% of a lamp with a CRI of 80]
Quote:
Originally Posted by BarraCuda™
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In order to create such a wide spectrum then multiple LEDs peaking at different wavelength would have to be mixed, look uniformed and pleasing to the eyes. Its easier said then done 
LEDs are not like FL or MH as it only have a very narrow spectrum. Ask for the spectrum chart of any single LED and you will see that the output will peak at a very narrow spectrum. |
It’s already done by Luxon. They have produced lamps with CRI’s of more than 90.
The CRI of the latest generation of LED lamps is 70 – 80 depending on the model.
Hardly what you’d call narrow band. If you doubt me go and contact them for yourself.
Quote:
Originally Posted by BarraCuda™
I'm only stating an example for the 1000 lumens at 1cm X 1cm spot. It is to illustrate my point that its worthless to have such brightness when the area covered is just a small spot.
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It has a 25 or 30 degree beam spread, the size of the lighting element itself is hardly the issue. At the two feet depth this is not 1cm across. To increase the beam spread you use multiple beams, to increase the intensity you simply overlay multiple beams. (This may well be enough to penetrate greater depth although I have expressed scepticism about this myself.)
Quote:
Originally Posted by BarraCuda™
You will need still alot of them to cover the entire tank.
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As we have been saying that from the beginning. Indeed the LED lamps offered are already of a multiple single LED configuration. The nature of LED lighing is that you have multiple relatively low output lamps to produce a large, more intense output.
Quote:
Originally Posted by BarraCuda™
No, 1 watt LEDs cannot produce 170 lumens as of today's technology.
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Throughout this entire thread I have asked you to provide a source for this claim or any supporting evidence. I myself am highly sceptical of this specific claim by this specific manufacturer. I am happy to consider anything you have based your statement on for the good of providing a further education source for other forum members interested in this subject.