View Full Version : Re: Compact Fluorescents - Lights of America brand any good, etc?

July 13th 03, 08:23 AM
On Wed, 18 Jun 2003 02:15:53 +0000 (UTC), (Don
Klipstein) wrote:

> Goes from reddish to bluish but yellowish is on the way from reddish to
>an only negligibly (and maybe only arguably so) greenish shade of white.

I know of few (if any) mercury-vapour fluorescent lamps thet emit a
true yellow wavelength. The proper propertions of red and green,
and of the right spectral positions, will appear just the same as a
single wavelength yellow to the human eye... BUT: in certain cases,
an object that reflects a sharp band in the yellow region and absorbs
quite a bit of red and green may appear less saturated and/or darker
(more toward a muddy greenish-brown) than a less selective
reflector/radiator. This was a _real_ problem with the earlier
cool-whites, daylights, etc, of only a decade or two ago. Of
course, this is the basis for CRI, as opposed to a true "Tungsten
Color Temperture". But tri-phosphors and polyphosphors are getting
better all the time, so I guess my first sentence might not hold
water much longer.

Isn't it true that (as I understand it, anyway) "Color Temperature"
rating of a fluorescent lamp is based on the perceived color reflected
back from a graybody, compared to the temperature of tungsten which
produces this same color? -or something like that...


Always listen to experts. They will explain what
can't be done and why. Then do it. - Robert Heinlein