A uk.d-i-y primer on LED lighting.



First there is no realistic chance of LED lighting becoming widespread
practical domestic lighting in 2 years. LEDs have too many and too
large issues.

They are excessive cost, low light quality, rapid deterioration of
output, and the fact that there are much better technologies around.

LEd lighting is a hype business. Other technologies show far more
promise, and have done all along.


Full spectrum lightig is another widely misunderstood subject. 3
discrete spectral lines can produce CRI of over 90%. People can not
normally tell the difference between 91% and 100%. Triphosphor lights
are widely sold as full spectrum, although theyre nothing of the sort.

Due to the nature of the human eye, full continuous spectrum lighting
is not needed.

Many non full spectrum tubes do look inferior, hence many have formed
the mistaken belief that full spectrum is needed for good eye appeal.
However in a lot of cases the lamps they were comparing were not as
described anyway, with discrete spectrum triphosphor lamps being
routinely sold as full spectrum.


12v halogens are the truest white of all domestic light sources, with
CRI of apx 100%, colour temp of 3000K and a full continuous spectrum.
As far as whiteness goes, theyre as good as it gets.


But this product is
attracting serious attention in stage lighting as well as automotive
headlights.

Serious hype, not serious attention. LEd lighting will not be taken up
any day soon by lighting professionals. This press release is aimed
directly at those without lighting expertise.


I've cross posted this to sci.engr.lighting so any errors or debatables
can be picked up by the real experts.


NT