No not rubbish, just very slightly off the mark. The human eye sees 3 colors that overlap a bit, so not really 'narrow" bands. It's a trick of the eye that makes color TV, color film and most color printing possible. If we saw more colors or a real continuous spectrum then color reproduction would be vastly more difficult.
So for your color mixing LEDs, you need only 3 colors - Red, Green, Blue. You may want to pick their wavelength centers to correspond to the human eye filters for best results (see SMPTE phosphors). If the 3 colors did not work, then your computer monitor, TV, LED video walls, video projectors, etc would not work. But they do.
A problem you may run into is that the colors don't mix well because of the space between the individual Red, Green, Blue LEDs. Diffusers or a tight pitch can help there.
I wanted to replace the 15 watt tubular bulbs in my aquarium with an LED so I ordered a 20 watt array chip from ebay. That 20 watts is like staring at the sun. In fact I'm sure it would cause as much damage as a MIG welder
It lights up my entire back yard better than any floodlight can. Needless to say it would blind my fish if used at full brightness. I never did use it for that though. The only drawback is the size of the heatsink required. I eventually used it at work to replace a very expensive mercury lamp in an optical comparator.
That 20 watts is like staring at the sun. In fact I'm sure it would cause as much damage as a MIG welder
Does it come with a warning for retinal damage? When I bought a Makita power drill it included the ML100 flashlight. Very very bright for short distances, not focused enough for long distances. It comes with a class 2 laser warning...
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So what you are really saying is that I need to pump more power into my amp for a cool lighting effect?
As expected with much more detail than I knew or remembered.
But very clearly, the paper shows, we "see" the whole range of "colour".
NOT
The reference shows more overlap than my old bio text's from school.
LED's are narrow band, so a set of three do not produce the full color spectrum. Technical LED Color Chart But by only producing something close to our three center bands, we get a reasonable approximation of white with less energy used. The above reference does not show LED's also produce IR. It only shows the useful visible bands.
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We have a Phillips Lumiled kitchen fixture -- the PWM does sing and the old dimmer has settings which cause the diodes to flash! We were also able to use a recessed LED fixture in the bedrooms -- fit in a pretty tight space where only a fluorescent could have gone before.
It's a very nice looking fixture and we were able to locate it above the kitchen dining table in a manner which nicely illuminates the table.
Saying this, however, the 3-way incandescent I have where I read in the evening also serves to keep me a little warmer -- and in the summer you don't have to turn it on until well after 8 pm.
CFL's remind me of the illumination in a Czech episode of "Sandbaggers".
So much overlap that we see the continuous spectrum.
Imagine a test set up using a single band of colour emission.
Now sweep that light from one end of the visible to the other end.
We see the light emission as a continuous spectrum.
If we had non overlapping colour reception, the swept colour would appear to go out between the narrow band receptors. That's not the way our eyes work.
I see the dimmer + flashing issue isn't unique to a single manufacturer's product. But then it's a Phillips... so the previous sentence may or may not be true...?
Does that lamp happen to be marketed as 'dimmable' via standard AC light dimmers?
Does that lamp happen to be marketed as 'dimmable' via standard AC light dimmers?
Most dimmers made for incandescents need a minimum load (e.g. 60-300 W). If you go below the minimum load, chances are the light may flicker. Dimmers made specifically for LEDs have no or a very low minimum load.
It's the way that my eyes work, but that's because I am colour blind. There are swept tests, one of which you can find on youtube, of a dancing mosaic. A small square moves about the field of grey stones and sweeps from one end of the spectrum to the other, with normal vision you see the square slowly sweep through the visible spectrum.. With myself however the colourful square disappears twice, once at each interval where the receptors are supposed to overlap, but in me there's a small gap instead.
Just like our hearing, it varies person to person. If anyone can find the test 5th mentions, it would be a fun test. Of course, you have to realize you are looking at it through a PC, whose display in also a set of overlapping bands based on the filters selected in the LCD. Trying to think how one could actually do a test like this. A hot-wire ( or sun) and a prism maybe?
The narrow band are relatively small, so I doubt a prism would really show this well. You might be able to see tiny colourless spots if you're colour blind, but I never have (not that I've ever been looking).
The computer might be an issue with the test, but from my experience it hasn't been. The first time I saw the test was when studying biology at A level. My biology teacher knew I was colour blind and not for my class but for another, she had told their teacher that I was, so when my class was in session and theirs was too along came the other teacher and requested my presence in their class because they were studying the eye and had this test set up. None of the other class had any student in it who was colour blind and they hadn't had the test explained to them before and indeed I hadn't been told what to expect either, but I guessed what was supposed to happen as soon as the test started. I was told to say what I see and when it got to the spot where the square vanished there were gasps of amazement when I said 'it's vanished'
This was on an old CRT monitor iirc and later on, on a DELL U2311H I performed the test again with my parents and they both saw the continuous colour changing square, where for me, it disappeared twice. I then performed the test again with my brother, he is also colour blind and I wanted to see if he saw things in the same way I did, or whether there were differences. There were however differences. We both saw the square vanish twice, but the size of the gaps between the different receptors was different for both of us, both in terms of size of gap and when the gaps started.
I think it's this one.
I'm know not colour blind, I passed an Ishihara test when I was seventeen when I was tested for military service (conscription). But in the video the colours do seem to vary in intensity, esp. when blue turns to purple they're only just present. Is this supposed to happen or is it the computer monitor?
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Cool. I just watched it with an old Toshiba laptop and it looked pretty uniform through all the colors, maybe just a tad light in the tan. I was waiting for an intense yellow or mustard but I never say one.
What does that say? Nothing much as the latop is an unknown. It probably says I don't have a significant problem. As least something in these old bones still works. I would bet almost everyone in this forum would get slightly different results and we would not know if it was eyes or monitor.
When I was suggesting a prism, I was thinking of a slot to get very narrow bands and not be constrained by laser frequencies.
What does that say? Nothing much as the latop is an unknown. It probably says I don't have a significant problem. As least something in these old bones still works. I would bet almost everyone in this forum would get slightly different results and we would not know if it was eyes or monitor.
When I was suggesting a prism, I was thinking of a slot to get very narrow bands and not be constrained by laser frequencies.
Yea... I was just wondering if that test would fail if the screen uses RGB OLEDs.
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