"Geoffrey S. Mendelson" wrote in message
...
Arfa Daily wrote:
Yes Geoff, I'm aware of all that. I work with the technology all the
time.
Did you read the original thread from last week ? We were not discussing
the
differences between transport and encoding systems, rather the moral - if
not technical - validity of Sammy advertising this new offering of theirs
as
a "LED TV", which it isn't. It's an LCD TV with an alternate form of
backlighting (LEDs rather than CCFL).

I have no idea of UK law, but in the US and here in Israel, if they use
LED's in the display, then they can call it an "LED TV". I expect the same
in the UK, I was watching a show from the first season of "The F Word"
(things
take a long time to get here) and they were discussing exactly what could
be
called a sasuage in the UK. Based on what I saw, I expect you would have
trouble fighting them calling a TV with a power on LED an LED TV. :-(


Considering the litiginous nature of U.S. society, and some of the consumer
product cases that William cited in a thread from a few months ago (Canderel
sugar substitute was it ? Something like that anyway) I'm surprised at that.
Also, Ramsay and his sausages is probably more of the exception than the
rule nowadays in the UK. Since handing over the running of our nation in
every way possible to faceless wonders in Brussels, we are so bogged down in
legislation about what we can and can't say about products that we can and
can't sell in ways that they dictate, I'm sure that someone will jump on
this sooner or later to say that unless it's at least 72.65% LEDs, you can't
call it a "LED TV" d;~}



One of the main selling points that they claim, is that because they can
control the intensity of the backlighting in individual areas, they can
deepen the blacks, effectively improving the contrast ratio.

In theory, yes they can. Since LCD's have very limited control over
brightness
then a variable brightness LED behind an LCD will allow them to modulate
the
light level of that particular pixel.


I think that I would have to contest your point of "very limited control".
All of the (recent) half-way decent LCD screens that I have seen to date,
have a perfectly adequate contrast ratio. Certainly, the one in my kitchen
produces deep enough blacks and bright enough whites to be absolutely fine
under the pretty intense flourescent light that I have in there. This is one
of the reasons that I question the requirement to extinguish areas of the
backlighting in order to 'improve' the rendition of blacks.


I don't know the resolution of the LCD array used in a TV set, but at the
actual crystal level, it's clear (on edge) or colored/transparent (face
out).
I guess if you modulated the polarizing signal you could get levels of
color
out of them, but I thought that the crystals were not fast enough for
that.

With HD now, the resolution of the panels is high, and the speed of them is
enough to cope with 100Hz refresh rates



On the example
that I saw last night, I observed no such improvement that was obvious,
compared to the sets around it. The reason that I questioned what
controls
for picture setup are available on this particular set, was that given
that
the backlighting is formed by RGB LED arrays, not white LEDs, then the
overall colour temperature would in theory be adjustable - sort of a grey
scale adjustment for LCDs, if you like.

Is there really such a thing as a white LED? The ones I have seen have all
been red/green/blue LEDS on the same substrate to produce what appears to
the eye as a white beam, most of which are far too blue for my taste.

They are blue because blue LEDs have a much shorter life than red and
green
so the color will change as they age, and they start out blue before the
end up
a red green mix (yellow/orange).



White LEDs do exist in a form that is not RGB based, and in fact is the
commonest form of them. They are blue LEDs with a yellow phosphor overlaid.
There is a wide variety of 'colours' of white available, including ones that
are distinctly bluish, and ones that are yellowish.



Someone - maybe William - commented last week in the original thread,
that
they had seen one in Fry's in the U.S., and that they weren't especially
impressed, either.

I have yet to be impressed by an LCD/PLASMA TV. Every single one of them
I have seen is oversaturated and too bright.


Well actually, the one in my kitchen isn't, neither is the one in my
daughter's lounge. The new Pan that I saw Friday in my friend's shop, was
excellent in that respect, giving an extremely nicely 'balanced' picture.
There are aspects of flat panel displays which cause me to like them less
than CRTs, but 'general' picture quality in terms of brightness, contrast
etc, is not one of them. I think that in general, they've got that one
nailed down now.

Arfa