"Rich Webb" wrote in message
...
On Sun, 24 Oct 2010 09:46:06 -0700, Jeff Liebermann
wrote:

On Sat, 23 Oct 2010 22:08:20 -0700, Jeff Liebermann
wrote:

On Sun, 24 Oct 2010 02:28:14 +0100, "Arfa Daily"
wrote:

Now the other day, the bulb in my Anglepoise bench light failed, and as
it
was the last 60 watt pearl one I had - nowhere stocking such an animal
any
more due to EU ecobollox intervention

More...

"Emission spectra of some compact fluorescent lamps"
http://web.ncf.ca/jim/misc/cfl/

You can check the spectra of some CFL lamps at:
http://www.lamptech.co.uk/Compact%20Fluorescent.htm

"The Double Amici Prism Hand-Held Spectroscope."
Emission spectra of various lamps are furthur down the page.
http://ioannis.virtualcomposer2000.com/spectroscope/amici.html
Incidentally, you might find it amusing to see what CCFL backlit white
looks like on a laptop LCD display [1.3.7], and a Sony Trinitron
[1.11.3]. Also, the authors comments on "Full-Spectrum Lamps" near
the bottom of the page.

Cool stuff. Always interesting to "see" that what we perceive is not
always (or often) 1:1 with what's really there.

Make Magazine vol 24 (due out any day now) will have a DIY article on a
hand-held diffraction grating spectroscope.
http://makezine.com/magazine/ (Note that as of today the link shows
volume 23; subscribers should have received an email link to number 24).

There's also http://sciencefirst.com/product_info...roducts_id=403.
It's kind of clunky (basically a kid's toy) but it does have an
adjustable scale so it can be kinda-sorta calibrated using a known
spectral line from a fluorescent lamp.

--
Rich Webb Norfolk, VA

I wonder whether colour blindness has anything to do with this, and the
reason why some of us seem to have a problem with the colour rendition of
CFLs, whilst others don't ? Long ago when I was in senior school, I was
tested for colour blindness, and was declared red blind and green
insensitive (I think) which I understood to mean that I couldn't pick out
certain shades of green amongst other colours, and couldn't see some shades
of red at all. In normal everyday life, this has never caused me any
problem, and as far as I am concerned, I see and distinguish colour as well
as the next guy, (although maybe differently in perception) but that is
assuming the natural condition of daylight, which all of the 'traditional'
light sources, including linear flourescents, mimic reasonably well, at
least at the lower end, and in terms of the spectra being reasonably 'bulky'
and continuous. However, that is not the case for the typical CFL spectrum,
which is *extremely* discontinuous. Could it be that the zero emission dips
in the spectrum, correspond wholly or in part, to spectrum sensitivity
deficiencies in my eyes, causing my colour blindness to become significant
under that light, and leading to some colours all but disappearing to me.
That would certainly account for why some blend colours like orange or
violet on the resistor colour bands that started all this, become
indistinguishable (to me) from the single colour components which make them
up.

Arfa