Arfa Daily wrote:
wrote in message
...
William Sommerwerck wrote:
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...
That's a reasonable definition for a video display, but it's not
sufficient
for source lighting. It's difficult to make a "full spectrum" fluorescent
lamp, especially one that produces good color rendition for photograpy.


but I guess even that varies depending on filtering effects of cloud
cover and haze and so on. Even so, I'm sure that there must be some
definition of 'average spectrum daylight', 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.
The standard is D6500, a 6500K continuous spectrum from a black-body
source.
What you suggest is, indeed, the intent.

TBH I think this is overplaying the significant of daylight. Almost
any monitor is adjustable to suit preferences of anything from 5000K
to 10,000K, and some go lower. None manke any attempt to copy the
colour spectrum of daylight, they merely include the same colour temp
as daylight as one of the options. None of the major display types
have any ability to copy a daylight spectrum, as they're only RGB
displays.


NT

But take account of the fact that we're talking domestic television sets
here, not computer monitors. For the most part, TV sets do not display the
same type of content as a computer monitor, and do not include user
accessible colour temperature presets or adjustments, which is why I made
the point earlier that in general, LCD TVs are set correctly 'out of the
box'.

As far as overplaying the significance of daylight goes, I'm not sure that I
follow what you mean by that. If I look at my garden, and anything or
anybody in it, the illumination source will be daylight, and the colours
perceived will be directly influenced by that. If I then reproduce that
image on any kind of artificial display, and use a different reference for
the white, then no other colour will be correct either, which was ever the
case when CRTs were set up to give whites which were either too warm or too
cold, even by a fraction. Maybe we're talking at cross purposes here, or I'm
not understanding something properly, but it seems to me that the colour
temperature and CRI of the backlighting on an LCD TV, would be crucially
important to correct reproduction of colours.

That's exactly correct. The colour temperature of the reference white
(ie; the WB) is vitally important for correct colour rendition. The eye
will adjust to an incorrect WB, but it will still be incorrect.

All I know is, is that the flesh tones were poor on the example that I saw,
compared to other LCD TVs which were showing the same picture. The
fundamental difference between those sets and the Sammy, was the CCFL vs LED
backlighting, so it seems reasonable to draw from that, the inference that
the backlighting scheme may well be the cause, no ?

It's just as likely that, as you said, a salesbunny wound up the colour
control to make the image "look better". Go knows that it's common
practice in showrooms.


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