Re: Leds colors, just wondering...

From: John Popelish (jpopelish_at_rica.net)
Date: 12/21/04 

Date: Mon, 20 Dec 2004 19:13:39 -0500

martin wrote:

> But if I may, so your saying that the color of the LED is not caused by the
> plastic surounding the little diode device? Do they put it in a RED medium
> to enhance the color.

The colored plastic makes it easy to tell what color light the LEDs
will produce when they are off, and increases the on to off contrast
in many applications. The dye darkens the appearance when no light is
coming out.

> What would happen if you put a Red "photon" inside a clear LED or can you
> have a clear bright photon inside a red plastic LED.

You get red light when it is on, and a but not internally illuminated
object when it is off. If you are not interested in looking at the
LED, directly, but shining a beam of red light on something else, the
clear lenses are usually used. 

-- 
John Popelish

Relevant Pages

  • Re: More on lights.
    ... White light includes red light. ... night vision, but cone cells give us color and detail perception. ... LEds are typically made by either blending light from multiple ... LEDs are available in a variety of wavelengths. ...
    (rec.bicycles.tech)
  • Re: More on lights.
    ... research which in turn revealed that red lights are better for vision at night as they highlight obstacles with much less depth perception issues and, whilst highly visible to those around are much less blinding. ... Rods give us our night vision, but cone cells give us color and detail perception. ... Red light can be used to preserve night vision because night vision is insensitive to it. ... White LEds are typically made by either blending light from multiple monochrome LEDs or by exiting a blend of phosphors with a monochrome LED. ...
    (rec.bicycles.tech)
  • Re: More on lights.
    ... White light includes red light. ... Rods give us our night vision, ... us color and detail perception. ... LEDs or by exiting a blend of phosphors with a monochrome LED. ...
    (rec.bicycles.tech)
  • Re: red light source, for animal watching
    ... I don't know the accuracy of sensitivity claims of animals to red light, ... Check out the high power LEDs such as the Luxeon and Cree brands. ... One is what the actual sensitivity of mammals to red light is. ... This is worth experimenting with, and if it does the job, you could get a permanent rig with glass filters and proper housings, waterproof, etc. ...
    (sci.engr.lighting)
  • Re: suggestions for red light
    ... The simple fact is that by means of adapting the eyes to low light conditions which makes the interior of the eye more transparent one can see far more objects and fainter objects than one otherwise could if the eye is light adapted. ... Facts are facts. ... LEDs, even red ones, produce too much light at frequencies other than red. ... The cones of the eye are sensitive to red light, and the surrounding rods are not. ...
    (sci.astro.amateur)