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New Telly Advice

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Old November 6th 13, 09:13 PM posted to uk.tech.digital-tv
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Default New Telly Advice

On 03/11/2013 21:10, Steve Thackery wrote:
Woody wrote:

The poorer the quality of a digital signal the more work the
processor has to do to correct it, and IME this can show up as an
less than perfect picture.

What? This is nonsense! Either your claimed signal degradation can be
error corrected, or it can't. The error correction algorithms are
clear. It has nothing to do with how much "work" the processor has to

If there are enough errors to exceed to capability of the error
correction algorithms, then you'll get picture corruption. If not, you

It's a misunderstanding of how error correction circuits are
implemented. There is no difference in processing power required if the
signal is perfect or it has errors. The processing to extract the data,
the processing to check the data and the processing to extract the
correction data will operate in parallel 100% of the time.

The misunderstanding probably comes from the Hi-Fi experts who used to
paint the edges of a CD with 'special' green felt tip pen so that the
error correction circuits didn't have to work so hard - thus improving
the audio quality.

Old November 11th 13, 07:27 PM posted to uk.tech.digital-tv
tony sayer
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Posts: 5,001
Default New Telly Advice

In article , Steve Thackery
scribeth thus
tony sayer wrote:

Come around to ours and have a look at our Bravia and see if you can
see any back light bleed as I've been looking for it for a long time
and haven't found it yet;!..

Actually I had a Bravia with edge lighting - that bled so I sold it.
Currently I'm using the Sony KDL-55HX923 which has a white LED array
for the backlight with local dimming.

Of course I haven't examined every single Sony, but there are two
fundamental problems with all LCD displays:

1/ No LCD cell can switch all the way off

2/ Edge lighting - even segmented into 12 or 16 zones like Samsung -
cannot completely darken a zone without significant interference with
other zones on those horizontal and verticals.

Thus I would argue that, subjective issues aside, it simply isn't
possible to get zero-light blacks if there is any other part of the
screen with picture content. Unless, that is, you are running a
backlight array with local dimming.

HAVING SAID THAT: I am happy to accept that your Sony may be so well
sorted as to be EFFECTIVELY perfect in normal use. Would you care to
tell me the model number? I'd like to read up about it, if I may.

Right.. Soz this has taken a bit of time but it's a KDL40EX503U

Quite frankly I use it to watch TV programs with and I cannot say I've
noticed any backlight bleed or other adverse effects Steve. The only
problems I have noted are those which the broadcasters don't get right!

A copy here of a review on the set which mentions its backlight system

Of course the sound on the internal speaker is fine for listening to the
news but for any serious stuff externals are needed like all modern day


Regular readers will know that I've had more than a few inconsistent
backlight problems with recent Sony TVs. So a good place to start my
assessment of the 40EX503’s pictures is by saying that its black level
response is really outstanding, and the dreaded ‘light pooling’
phenomenon is almost non-existent - or, at least, is barely visible over
what I’d estimate to be less than 5 per cent of your overall viewing

The black levels achieved during really dark scenes attain almost LED-
like depths at times, yet the amount of brightness the 40EX503’s dynamic
contrast system has to lose to make such black levels possible isn't as
drastic as I’d have expected. Which means, of course, that bright
elements in predominantly dark picture content still look reasonably
punchy, and dark scenes overall look agreeably dynamic. Another hint as
to just how clever the 40EX503’s dynamic contrast system is can be seen
in the good amount of shadow detailing the set retains in dark areas.

More good news finds the 40EX503 exhibiting an unusually deft touch with
colour reproduction, serving up generally immaculate blends and
transitions, and managing to reproduce even the trickiest, smallest skin
tone differentiation's with aplomb.

Some people might feel that the 40EX503’s colours look ever so slightly
washed out once the set has been calibrated to deliver its best all-
round results. But for me this is a small price to pay for what works
out to be predominantly very accurate colour tones that show source
material in the way it was designed to look, rather than the more crowd-
pleasing but ultimately less authentic approach favoured by more vulgar

Read more at http://www.trustedreviews.com/sony-b...-40ex503-40in-
Tony Sayer

Old November 12th 13, 10:58 AM posted to uk.tech.digital-tv
Steve Thackery[_2_]
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Default New Telly Advice

tony sayer wrote:

Right.. Soz this has taken a bit of time but it's a KDL40EX503U

No need for soz - this is just a low priority thing. :-)

It sounds really good in the review, and is very interesting.

Actually, I've long wondered why the manufacturers haven't all gone
over to the "local dimming array" system, at least on their premium
sets. It would seem to me to be an inherently better system, because
it has the potential to provide far more granular control over the
screen illumination, at the cost of a few hundred white LEDs. It's
hard to believe that Sony et al can't buy white LEDs for a very low

Anyway, thanks for going to the trouble of posting that review.


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