"Adam Aglionby" wrote in message
...
On 10 Sep, 01:03, Derek Geldard wrote:
On Tue, 07 Sep 2010 22:05:55 +0100, Tim Streater

wrote:
In article ,
"Arfa Daily" wrote:

I know many many people who hate them. They are a substitute
technology for
one that worked right in the first place.

Mmmmm no it didn't. Not really. What you want is visible light. So you
heat something up to a point where its peak output is in the infra-red,
with the tail of the curve being in the visible region. Hardly
efficient, is it.

No lamp can be described as efficient if the light it produces is not
fit for the purpose for which it is required.

A lamp which produces a dozen or so practically monochromatic spectral
lines is useless for many purposes involving fine work or colour
matching, even if the spectra can be chosen so that the eye, using
tri-stimulus colourimetry, percieves the light to be the same colour
as daylight. Suite materials, yarns and dyes etc are never matched
with fluorescent light, and for that matter neither is cloth
"invisibly" mended.

Not entirely true, fluro is used in colour critical applications, can
get better than 90 CRI with linear tubes.
But at a very cool colour which really dosen`t suit living spaces.

Everyone know involved with lighting , whatever they sell for a day
job, use halogen at home....

Cheers
Adam

I want something that produces a band of frequencies in the visible,
with nothing beyond. Anything else is a hack.

It's not what we need, natural daylight is not like that.

Derek


Just taking up the colour spectrum issue. Going back to the P.O.S. CFL that
I bought to fit in my new hallway lampshade that started all this. Up until
last night, despite the fact that it splutters to life - that really is the
best description - and the light output that it gives is nothing like
adequate for about the first minute, I had left it in place, but switched on
most of the time so that I didn't have to wait for it to start pretending to
be a light bulb. So there's the 5 minutes at 60 watts versus 5 hours at 11
watts argument, neatly encapsulated in unthinking reality, immediately ...

But last night, I finally gave up on it for another reason entirely. Our
hallway has a dado rail about half way up. Above it, we painted the walls in
a colour called calico. It's a sort of pale but rich creamy tone. Below the
dado, we have put wallpaper. The background is an almost identical colour to
the paint. The pattern is leaves, with a very subtle textured gold finish.
Hard to describe and not sound tacky, but the missus has a designer's eye
for this stuff, and it really does look lovely. Then, one of our daughters
came round last night, for the first time since we did it, and immediately
declared that she didn't like the colours. We asked her what she meant, and
she said that she didn't like the green of the leaf pattern, and she would
have thought that we could have found a paint that matched the background
colour of the wallpaper a bit better than the one we had got. And you know
what ? Under that light, she was absolutely right.

I immediately removed the CFL, and committed it to the junk box, where it
can languish until I decide to use it for lighting the loft, or to chuck it.
I took a standard 60 watt incandescent bulb from another little-used
fitting, and put that in the hallway instead. "Ah", said the daughter,
"that's better" ! And you know what else ? It was ... Much better ...

Arfa