From: John Popelish
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Subject: Re: Deep red, ultra bright LED manufacturers?
Date: Wed, 30 Oct 2002 23:48:01 GMT
NNTP-Posting-Date: Wed, 30 Oct 2002 18:48:01 EST
> In article , "Jeroen" wrote:
> >"Malcolm Reeves" wrote in message
> >> Hi,
> >> Can anyone suggest manufacturers for deep red, i.e. >640nm wavelength,
> >> and ultra bright, say 2500 mcd (30deg angle).
> >> The ones I have found so far are www.femacorp.com and www.lumex.com .
> >> A few others have them, that I have found, but not bright enough at
> >> 30deg, i.e. sharp, agilent, and UOE.
> >try www.lumileds.com... they make 1W and 5W LEDs that are incredibly bright.
> This brings up a point I had been thinking about. I noticed a long time ago
> LED's were about the only red you would ever see behind a car. All lamp
> based tailights have a orange cast, not red. So I noticed the other day a
> newer car with LED's with that same orangish cast. Well I guess it might have
> more presense compared to deep red, not sure, but interesting.
> Railroad lamps always had a deep red, not orange cast to them.
The eye is about twice as sensitive to red-orange light than it is to
pure spectral red. So if you are trying to get someone's attention,
deep red is not the best color.