I found the early CF bulbs had rather lousy spectral characteristics and
also lousy ballasts. The more recent ones have a much better output
spectrum and the high frequency ballasts are much better, no flicker or
problems with strobe effect.

Halogen lighting is nominally about 3,200 degrees kelvin color
temperature and daylight is typically considered at around 5,500 degrees
(that varies a bit or course). It's a little more complicated than just
color temperature though it's also a function of the output spectrum.
Fluorescent lights, particularly the older ones, emit light at a few
specific wavelengths where halogen and incandescent emit across a much
wider spectrum. Even if the apparent color temperature is the same the
light may not look the same due to missing wavelengths.

The newer CF lamps have much better phosphor blends and fill in many of
those gaps. The earlier fluorescents were particularly heavy on some
green wavelengths. They now have fluorescents with specifically blended
phosphors that have strong red, green and blue output bands to match the
needs of video lighting use. Replacing 20kw of halogen studio lighting
with 5kw of fluorescent is a big power savings on the lighting alone and
also on greatly reduced air conditioning costs.

I find the best way to select the CF lamps is to look at them in the
operating display most stores seem to have to get an idea of what they
look like and then bring the one that looks best home for testing.

The human eye can do some very interesting color balancing so it is more
important to keep the lighting in a given area consistent that to have
it a specific color temperature. If you want a good test of this
balancing ability, try looking into a video camera with a B&W viewfinder
for 10 min or so while keeping your other eye open. You'll find the the
eye that has been in the viewfinder sees it as "real" black and white
while if you look at it with your other eye it appears blue and white.

The only things I find that takes a little getting used to is the 1/4
second or so turn on delay and the minute or two to come up to full
brightness. I have several 42w CF lamps in the cheap spring clamp
reflector shades that have replaced the 500w halogen floodlights as work
lights for many projects.

Pete C.



Shawn wrote:

Recently our local power company has been recommending replacing
incandescent bulbs with compact flourescent for energy savings. I've found
that the color of these are rather harsh and that the colors also vary from
one manufacturer to another. Sometimes the color temperature is listed on
the package but without something to reference it to, it is worthless to me.
What is the color temperature of a standard incandescent? Better yet, I
like the color of halogen bulbs, where do they fall?

Thanks,

Shawn