Hi Jez, Chuck and all,
From: Jez Cunningham <jez@xxxxxxxxxxxxxx>
>"and now the EU is banning incandescent bulbs" - a slight exaggeration -
but
>it sure gets up my nose anyway :-(
See <http://www.consumer.philips.com/c/energy-saving-light/23289/cat/gb/>
and click on the 'EU directive' tab.
From: Chuck Norcutt <chucknorcutt@xxxxxxxxxxxxxxxx>
>What about LEDs as a light source? I think few could afford the likes
>of this but it shows the advantages: low power requirement, little heat,
>completely dimmable and color temperature just dials in.
<
http://www.bhphotovideo.com/c/product/653087-REG/Zylight_26_01013_IS3_LED_Light_Kit.html#features
>
Well, this one is a high end solution, quite expensive... It seems to have
red, green and blue LEDs automatically balanced to get such a broad range of
temeperatures -- or, more accurrately, the equivalent tristimulous, which is
_not_ the same thing in every situation.
"White" LEDs are an awkward thing -- they're really _blue_ LEDs with a
yellow phosphor... the combined emissions give a whitish light to the eye,
and the spectrum is continuous... although far away from "uniform", with a
large peak around the blue wavelengths. They are a well known source of
metamerism problems, but still are way better than (most) CFLs for a
lighttable, according to my experience.
>Where will LEDs be in 5 years?
Who knows! I remember when _blue_ LEDs were simply NOT AVAILABLE...
From: Jez Cunningham <jez@xxxxxxxxxxxxxx>
>There are quite a lot of LEDs appearing in domestic light bulbs now, and
>they have the advantage in being a bit more environmentally friendly that
>CFLs (if you're of that persuasion).
CFLs have another (related) problem with short-cycle usage, e.g. bathroom
lighting -- their life could be reduced to as little as 20% of their
long-cycle estimation, ruining both economy and environmental advantages :-(
LEDs seem to be the future, but they're still too expensive for domestic
lighting.
>But for me the good ol' incandescent
>still reigns - albeit progressively migrating from 'tungsten' to 'halogen'.
>jez
Sure! I'm getting some Philips halogen with standard E27 mount -- even at a
EU-directive-waiving 105W (150W equivalent!!!!)
Cheers,
--
Carlos J. Santisteban Salinas
IES Turaniana (Roquetas de Mar, Almeria)
<http://cjss.sytes.net/>
--
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