In article ,
"Mortimer" writes:
"Tony Quinn" wrote in message
...
In message , Andrew Gabriel
writes
"Andy Champ" wrote in message
et.uk...
Lumme that stirred it up - and it was only the RF pollution I mentioned!

A couple of points guys on that long discussion:

Colour Temperature - the CFL is a lot closer to daylight for our
3-colour-sensor eyes than the old incandescent. I daresay people said

Daylight covers a wide range, from dawn (2100K), through to midday
(5600K), through to just before twilight (2100K). Incandescent (2700K)
is a damn good match for daylight at the time we need to start enhancing
light levels for our own comfort at home. What we in effect do in our
homes
is stretch out the early evening period before twilight for which daylight
is 2700K way into the evening/night, both at the colour temperature and
comenserate lumen level (illumination level).

That's interesting because I've found that twilight/dusk are actually very
blue (ie higher colour temperature): if I white-balance my still camera off
a sheet of A4 paper that's outside at dusk, tungsten interiors (real
tungsten or tungsten-balanced CFL) look horrendously red. Using the same
white balance in daylight (either sun or shade) also looks quite orange.

See my other post about having to average across the sky.
Of course, once the sun has set, you only have the blue sky
as you are in the earth's shaddow (hence my reference to
"just before twilight", or perhaps I should have said, just
before sunset). That is unless you have clouds which can
still see the sun and reflect the direct red path back to
ground (i.e. "red sky at night")!

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]