In article , CJT wrote:
wrote:

Yet another good reason to replace with fluorescent- of appropriate
output. Halogens are so "sixties." :')

J

I think halogens generally produce "whiter" light, though. My wife
has a brown sweater that looks green under fluorescents.

The "old tech" Cool White fluorescents caused complains with teir color
rendering index of only 62.

"Old tech" Warm White had a color that looked like it should be OK, but
its color rendering index was/is only 53. One bad color distortion that
one does is making skin tones more greenish-yellowish-pale than they
appear under incandescent, halogen or sunlight.

After that came "broad spectrum" fluorescents. They had color rendering
index as high as close to 90, but at the expense of about 30-33% less
light. Although their color distortions were much less, they were in the
same direction - making skin tones less pinkish and making most reds and
greens darker and duller, and blues violetish.

Now, we have compact fluorescents as well as triphosphor
linear fluorescents in two grades.

Compact fluorescents (excepting mainly most dollar store models, "full
spectrum" ones from pet/aquarium shops and the rare, largely obsolete
FUL tyes) and the upper grade of linear triphosphor fluorescents have
color rendering index 82 (sometimes a bit more for larger linear ones),
and their color distortions are in a more pleasing direction - skin tones
are slightly excessively pinkish, and greens and reds are more vivid and
brighter than "proper".
These are not perfect - bright pure reds come up slightly orangish, and
some blues under the warmer color ones of these lamps still come up
slightly violetish. But an earth tone sweater will probably not be made
greenish!

The "upper" grade linear triphosphor fluorescents have color code SPXxx
if by GE, D8xx if by Sylvania, and 8xx if by anyone else. xx is the
2-digit abbreviated color temperatu

27 - incandescent-like or close (most compact fluorescents)
30 - "warm white color" - slightly whiter or pinkish-whiter than incandescent
35 - "whitish warm white" - I find that one really pleasant!
41 - "cool white"
50 - an icy cold pure white that sometimes looks slightly bluish

In most home use, 35 or less is recommended. 41 or higher can cause a
"dreary gray" effect unless lighting level is "office-bright" or
"classroom bright" (near or over 100 footandles / 1100 lux).

Keep in mind that in home centers, the T8 (1 inch diameter) triphosphors
will be the lower grade - 7 instead of 8, or SP instead of SPX if by GE.
The lower grade, although better than "old tech" (halophosphate phosphor),
has a color rendering index in the upper 70's rather than low-mid 80's,
and is not quite as good as "upper grade" in pleasantness of any color
distortions.

- Don Klipstein )