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I am curious about why people don't suggest this 48 inch pent 0.5W light? According to all the people listing them the lumen output is way above many comparably sized 1 or 3 watt LED arrays from the same company. In addition they spread the light out more meaning you are more likely to a more even lighting which will make it easier for more leaves on more plants to catch a few rays.

Recently I was trying to pick some beamswork lights and I couldn't find any spec or reason to go with the simpler 3 watt LED arrays over these unless you want to modify them. It just seems they are more efficient LEDs period and so you get more light / watt and in most cases more total light period.
 

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The light you are mentioning is not the pent 0.5 W its the triple 0.5W

The first light you mention is this one I believe. And aquatraders sells it for $92.97.

The second one is this one and it is $52.98 almost $40 cheaper. And puts out the same amount of light in half the electricity usage.

But this thread is about a deep tank that will require more light and the light I linked is this one. Which is $79.97, that is still $20 cheaper and puts out 57% more light.



While you may suspect the wattage measurement is not accurate unless someone measures it differently we need to make decisions based on what specs they release. And we don't know they are liars yet to discredit their specs. Second it would have to be really different because the difference is huge, almost double the efficiency. Right now the first bulb is half as efficient for the same output of light. So the only thing left is the OP has to spend more money on optics and calculate or know those optics will lead to at least a 60% increase in the intensity of light deeper down. All of this means either I am missing something or other people here have real measurements that point to the 0.5W arrays performing significantly worse than they are speced in power consumption or light out put or some combination of both. But if a company was lying that bad I think it would come out. I personally purchased 3 of the pent 0.5 W leds and measured their LUX with my phone under some fairly diffused conditions and still came up with what I thought was pretty good light. looked to be at least 80 par at 15 inches. This was after they passed through privacy glass that scatters light which I use on my vivariums to hide the upper infrastructure. Unfortunately I do not have the 3W arrays to directly compare but I am noticing in many places a bias against these new 0.5W arrays that I do not understand.
 

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I am not completely following what the main point of your post is, are you suggesting that beamswork and sellers are falsifying the specs on the 3W leds to make them look far worse then they actually are? Or lying about the specs on the 0.5W arrays? Why would they do this on a more expensive product they carry? One that should also be easier to assemble given you don't have to solder on hundreds of tiny SMDs to the 0.5W units.

I understand if you are going to modify this you want the 1 or 3W arrays because you can easily purchase and replace or add optics. But I think if that is the main motivation it should be asked if the OP is willing to do all that work. Most people who purchase pre made lights do so because they don't want to do extra work. And it should be brought out to the OPs attention that these are only better if they OP is willing to pay more and do more work.

I do not think it is fair to assume they liars and use that as evidence to suggest another product they sell. It's kinda weird its like saying oh well ford lies about the focus and makes the efficiency look too good so you should buy an F-150 its probably more efficient than ford claims. Why wouldn't ford be lying about all of their line in a similar direction? Why would they only lie about some of them? Without independent verification we shouldn't be assuming that the older model 3W are way better than they are speced or the newer 0.5W are way worse or any combination in the middle.

In the thread you linked another person measured wattage on a 30 inch pent LED and came out with 56W which is right in line for the fixture he purchased. I also have 3 of these and I used a ubiquity mFi to measure 2 of them and they both read about 48 watts for a 30 inch fixture note that my device often reads lower than the stated specs by a little.

So IMO we have a few verifications that the wattage they claim is not far off. I have also measured the LUX and the 30 inch fixture has higher light than a 36 inch finnex ray 2 once again more evidence these are powerful lights.

So someone is going to have to dig up any numbers that have been released for the 3W figures in order for anyone to claim that something is wrong with the specs of that one. IMO unless such informations surfaces then we should stick to making decisions based on the manufacturer based specs and avoid guessing about all the complications involved in electronics.
 

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I understand all of that, but it doesn't answer the question why do you think the 3W are likely to be somehow better in actual performance?

How many real Lumens do you think the 3W and 0.5 watt arrays are putting out? And why do you think the company would lie about one and not the other?
 

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So if I interpret this right you feel that 95 degree optics is enough to focus more than 60% of the light to make up for the difference?
 

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Well if its anyone's guess then we cant really be recommending one over the other can we? Because all this theory is only applicable if we can use it to calculate the gain and know that that gain will result in more PAR at depth than the cheaper, more efficient light that just puts out more lumens. For instance if you assume that 120 degrees is wide open optics, and 95 is what you have then you have a 25 degree concentration of light. Looking at BMLs site we see that a 30 degree increase in optics from 90 to 60 degrees only results in less than 20% increase in PAR at 24 inches between 2 equivalent lights. So unless you have a good calculations or good measurements that can show otherwise I don't think it is fair to point people to the 3W fixtures without real evidence they are going to be better.

I think every one knows that if you have 2 equal lights that the one with a more acute angle for optics will win. But we aren't talking about a system that simple. And so far you have presented tons of descriptions of the basic physics but when pressed for how you could apply it to real numbers in this system you always stop short of doing the back of the envelop calculations needed to give us some estimates of real PAR or lumens. Without either calculations that show worst case and or best case scenario gains or actual measurements we should not be recommending 1 light over the other.
 
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