Curious white led observation

jeff1500

Enlightened
Joined
Jul 9, 2001
Messages
417
I have a four white led light that I'm very happy with and use just about every day. But that wasn't always the case.

I built it myself and when I first got it going it gave my eyes kind of a weird feeling when I used it in normal ways. It's like I couldn't adjust my eyes to the hot spot in the beam. I made a light green filter to remove the blue cast in the beam but still the same funny feeling.

Then I ground the round tops off the white leds and polished them smooth with toothpaste and the funny feeling in my eyes went away when I used the light. That was a few months ago and I've been using it very successfully ever since.

I have some red and yellow leds with round tops and hot spots in the beam but I don't get the same funny feeling from them. I also tried the same thing with a regular flashlight. No problem. As far as I can tell, the funny feeling I get is only when I use round top white leds.

I just moved on and wondered if there was something funny going on with my eyes because of all the dry winter air and allergy stuff and all that.

Today, after not thinking about this for quite a while, someone showed me a three white led head lamp they got at the backpacking store. I tried the same experiment. I found a dark corner in a lighted room and shined the beam on an object about three feet away, and sure enough I got that same funny slightly overexposed feeling in my eyes.

What do you think about this?
 
"What do you think about this?"

I think you are crazy ;-)

No, really, I think I know what you are talking about- ... maybe...

Laser beams usually do that to me, and a couple of times, I have felt .. seen?... a similar effect from LEDs, although I can't recall seeing it from WHITE leds-

There is probably an explanation for this, but I don't know what it is. I'll bet Craig or one of the other more scientifically knowledgable folks here has the answer
 
I have no idea what's going on here. My eyes seem to like white LEDs just as much as any other multispectral light, like incandescent, fluorescent, or sunlight.

Without being able to try your eyeballs in my eye sockets, I couldn't even begin to guess what's going on; or whether what you're "feeling" is physiological or psychological; or maybe a smattering of both.
 
I don't think sanding the top would change the color but it would soften the shadows and make the light more natural and less pinpoint.

But thats an interesting question.

What is led white?

Could someone with a prism break the beam and see what colors pop up?
 
<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by duffahtolla:
Could someone with a prism break the beam and see what colors pop up?<HR></BLOCKQUOTE>

Been there, done that, got the t-shirt thankyouverymuch.
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The spectrum is deficient in violet and blue-green, and strong in mid-blue.
 
i've noticed this in certain situations. it was especially apparent when i was underground with a lightwave illumiator that needed new batteries. my eyes seem to be playing tricks on me, probably more because the illumination was less than it should have been more than the fact that they were LEDs.

try using more LEDs/more light and see if that helps. or perhaps just refreshing your batteries.
 
<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by duffahtolla:


Could someone with a prism break the beam and see what colors pop up?
<HR></BLOCKQUOTE>

Thanks Craig
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My theory is that I'm not real sensitive to some particular light frequency, or maybe oversensitive to some frequency, so when there's a fuzzy change in brightness with position, my eyes don't adjust the the right iris opening.

Funny thing. But like I said, I grind the tops flat to get a smooth pattern and then I'm happy.
 
There have been cases of photo-induced epilepsy for people not typically inclined to seizure. It to about 7000 children in Japan a few years ago during the airing of a children's animated program (Pokemon, if I'm not mistaken), prompting The Simpsons "Giant Seizure Robots." ; )

Another case was reported in the UK a number of years ago during a few weeks each year. Sunlight at the correct angle, strobing through evenly spaced trees as automobiles passed by caused several seizures and accidents.

Certain frequencies of light and/or flash rates have also been known to trigger migraine headaches.

You may want to speak to your doctor about this.
 
Yeah, ever read the warning that accompanies most video games?? As I understand it certain sequesces were taken out of Pokemon (I would be quite content if all 30 minutes were taken out but...) before it came to the US...lawsuits ya know
 
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