Arfa Daily wrote:
"William Sommerwerck" wrote in message
...
The LCD only filters light from the backlight. If you don't have a full
spectrum white in the first place the you can't expect decent colour.
White LEDs aren't quite there yet are they?
Absolutely true, except that this particular TV doesn't use white LEDs in
its 'revolutionary' backlighting scheme. It uses small RGB arrays, which
is
why I was questioning whether there was any control over the individual
elements in each array, such that the colour temperature of the nominally
white light that they produce, could be varied. Which would then, of
course,
have a corresponding effect on the displayed colour balance. It just
seemed
to me that given they have gone to the trouble of using RGB arrays,
rather
than white LEDs, the reason for that might have been to get a full(er)
spectrum white.
In a very broad sense, the last thing you want is a "full-spectrum" light.
The standard primaries are diluted with too much white as it is.



I guess it comes down to definitions and how 'full spectrum' is perceived.
Rightly or wrongly, I tend to think of it as a spectrum which contains the
same component colours in the same ratios, as natural daylight, but I guess
even that varies depending on filtering effects of cloud cover and haze and
so on.

It does. One specifies that with colour temperature. Eg; direct sunlight
is about 5000K, while shade is up around 6500K, & tungsten light bulbs
are down around 2400K. Higher temperatures are biased towards blue,
lower are biased towards red. The white balance of a screen or an image
is specified in the same way.


Even so, I'm sure that there must be some definition of 'average
spectrum daylight',

There is: 6500K, which is what I have my monitors calibrated to.
Traditionally, the print (CMYK) media use 5500K.

and I would expect that any display technology would aim
to reproduce any colour in as closely exact a way as it would appear if
viewed directly under daylight.

In general, that's true, although it's common for LCD monitors to have a
factory WB of as much as 8000K, as it makes the image zappier.



--
W
. | ,. w , "Some people are alive only because
\|/ \|/ it is illegal to kill them." Perna condita delenda est
---^----^---------------------------------------------------------------