On 9/18/06, RampantNM@aol.com <RampantNM@aol.com> wrote:
> I'm confused, although some would say that's not hard to do. When I wear
> red tinted sun glasses, it seems to filter out the red, so landscapes appear
> greener. I thought a red lense would filter the red light. Do they filter
> white light out of our current incandesent bulbs? Isn't "white" light a
> combination of all the colors?
Red lenses filter out everything *except* red.
However, our perception of colours is very complex. There are
compensating mechanisms that allow us to see even when the light is
not white without noticing the colour offset. For example: at night,
we use incandescent bulbs, which emit light that his really rather red
-- the blue end of the spectrum is missing. Yet, we don't perceive
this. Or rather, we do, when we see some white light: such as that
produced by HID headlamps (which looks blue because the ambient light
is skewed towards the red end of the spectrum).