Gregg wrote:
I think both lights have its niche. I have two of the newer expensive
ones. They definitely don't produce the same amount of light, though
I'm sure their data says otherwise. I just use the simply "common
sense" test. Pretty simple IMO, hold up an open book and look. Which
type of light makes it easier to read? Until they come up with an even
better type of lite that emits more lite, my majority of bulbs will be
the usual.

The problem is that incadesecnt lights are truely a full spectrum device.
They emit waves from far infrared (heat) to near ultra-violet over a
continuous spectrum.

Most of their output is far infrared, about 90% of the total, and by the
time they get to ultra violet, it's negligable.

Floursecent bulbs emit only ultraviolet light inside, and use that to excite
phospors on the outside of the bulb. They absorb most of the UV light, and
emit single color light. Household bulbs use a combination of the 3
primary colors of light (red, green and blue) to produce what looks like
(but really is not) full spectrum light.

LED's also work the same way, combining but they emit the colors directly.

Both are combined in such a way as to look white. The problem is that the
colors are generally set up to mimic daylight, (the light of the sky
on a clear day), not sunlight. The human eye is used to seeing sunlight, and
is more comfortable reading with it.

Incadescent light is the most comfortable for reading, being more like
sunlight (actually it is even more red).

As far as efficency goes, incadescent light is about 10% efficent, although
there are more efficent and longer lasting bulbs around, they have never
really been markted effectivley.

LED lights are about 25-30% efficent due to problems with heat dissipation,
the fact they are DC devices in a world with AC power and so on. There have
been claims of almsot 50% efficency in the future, but so far they are just
claims.

Flourescent lights are around 35% efficent, which currently makes them the
leader in lighting.

It's IMHO actually a false claim because due to the difference in spectrum
output, I find that I (and my family) all need higher power lights to read
if they are flouresent. That's why although I've been using CFL's for 13
years or so, we still have reading lamps with incadescent bulbs in them.

What I am hoping to see is a varation of the 360 degree LED with improved
efficency. These are similar in design to flourescent lights. The LEDs are
encased in a block of plastic, which instead of clear like traditional
ones flouresceses (glows).

The ones I have been using to replace radio dial lamps glow brightly in
a daylight white color in all directions, I'm hoping to be able to
buy them in "warm" (redder lights for reading) in the near future.

Until then, IMHO you are wise to replace all of your incadescent lights
for general illumination with flourescent ones, the "regular" kind being
cheaper to maintain than CFL's, but to make sure you have a large supply
of replacement bulbs for your reading lights.

Geoff.

--
Geoffrey S. Mendelson, Jerusalem, Israel N3OWJ/4X1GM
New word I coined 12/13/09, "Sub-Wikipedia" adj, describing knowledge or
understanding, as in he has a sub-wikipedia understanding of the situation.
i.e possessing less facts or information than can be found in the Wikipedia.