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Re: Long life lights

snipped-for-privacy@manx.misty.com (Don Klipstein) wrote in news: snipped-for-privacy@manx.misty.com:

[snip] >>Instead of using white LEDs would it not be possible to use a number of >>red, green, and blue LEDs create the effect of white light? > > They actually do that. It gives a wierd color rendering effect - with > red objects coming out "day-glo" bright and wood tones coming up very > reddish/pinkish. Oak has a color like that of mahogany. Skin tones > come up reddish. > > - Don Klipstein ( snipped-for-privacy@misty.com)

Interesting. Would colors look more true if, in the lamp design, one combined 2 green LEDs , 2 blue LEDs, and only one red LED...?

Reply to
Kris Krieger
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Colors would probably appear "better", but the overall color of the light would be quite bluish.

Heck, equal numbers of R, G and B LEDs often results in bluish light.

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- Don Klipstein ( snipped-for-privacy@misty.com)

Reply to
Don Klipstein

snipped-for-privacy@manx.misty.com (Don Klipstein) wrote in news: snipped-for-privacy@manx.misty.com:

Oh, so then, it wouldn't offset the "day-glo red" effect :(

Although you've gotten me thinking about a possible variation on the "flickering candle" LED lights- since a candle flame actually consist ofa progression of colors (basically, very small blue core, large white band, moderate yellow band, and small red band), I'm wondering wbout setting up a series of flickering LEDs in that sort of pattern. That's just off the very top of my head, but I'm trying to picture whether it'd look interesting- enough to put more thought into it.

Reply to
Kris Krieger

I have looked at candle flames enough, and it appears to me that over

99% of the light is from the whitish/yellow-yellow region, in the form of close enough to blackbody radiation at color temperatures in a range mostly within a couple hundred degrees of 1900 K.

If you put random noise through a narrowband filter centered around 6 Hz or so and have that modulate the brightness of a 1900 Kelvin source, that's already most of the way there. The next refinement would be to modulate the color slightly (maybe 50 Kelvin) - with color temperature varying inversely with brightness, maybe not exactly 180 degrees out of phase from brightness.

- Don Klipstein ( snipped-for-privacy@misty.com)

Reply to
Don Klipstein

snipped-for-privacy@manx.misty.com (Don Klipstein) wrote in news: snipped-for-privacy@manx.misty.com:

Er, that's a bit advanced for me...I'm just starting to teach myself a little bit about "555 timer" =:-o

But could you do all that modulating with an LED as the light source...? I thought they had fixed colors and could only get brighter or dimmer with changes in voltage. It'd be cool if you could actually modulate and LED like that.

I think that the flickering effect would be especially attractive inside of a clear-textured glass enclosure/construct.

Reply to
Kris Krieger

Actually for this case merely output modulating the longer wave (redder) length LEDs more deeply should do the trick.

Reply to
JosephKK

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