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William Sommerwerck
Guest
Fri Feb 26, 2010 4:19 pm
Quote:
Dolby has a new thing -- HDR LCD that
modulates the LED backlights on-the-fly.
This is neither new, nor was it invented by Dolby.
bob urz
Guest
Fri Feb 26, 2010 4:20 pm
Quote:
CRT TVs refresh at 50Hz or 60Hz (near enough) depending on region.
Since a TV program will only contain images (interlaced) at that rate -
or frequently less - a TV that purports to offer a higher refresh rate
will have to create the extra images by some kind of interpolation. If
it does a bad job, then the result will be unwatchable regardless of how
high the refresh rate is.
Sylvia.
It can get more complicated than that. Dolby has a new thing out HDR LCD
that on the fly modulates the LED backlights for brightness in groups.
that was not possible with CFL LCD backlights.
http://www.dolby.com/uploadedFiles/zz-_Shared_Assets/English_PDFs/Professional/dolby-hdr-video-technical-overview.pdf
bob
Chris
Guest
Fri Feb 26, 2010 4:47 pm
"AZ Nomad" <aznomad.3_at_PremoveOBthisOX.COM> wrote in message
news:slrnhoe848.bkr.aznomad.3_at_ip70-176-155-130.ph.ph.cox.net...
Quote:
On Fri, 26 Feb 2010 00:07:43 +0000, Adrian C <email_at_here.invalid> wrote:
On 25/02/2010 23:46, William Sommerwerck wrote:
First, the only televisions that use LEDs use OLEDs. There are none
using
conventional LEDs.
none ??
I think when they refer to LEDs, it is LEDs used for backlighting
probably for an LCD.
Yes, that is how it was explained to me from a salesman as well as what I
gathered from online info. So, apparently, it is still an LCD screen. Also,
somehow the refresh rate of the LEDs create some sort of multiplier effect
with the LCDs; thus the higher hz. It sure would be nice to know if this is
correct, and also why/how it enhances the picture.
Although I am far from an expert in this area (hence my original post), I
have the ability to understand just about anything that is explained
correctly. When information is presented in an ambiguous way, which is what
I have seen so far on internet research, that is definitely a red flag that
the author probably is not knowledgable in the subject matter.
William Sommerwerck
Guest
Fri Feb 26, 2010 4:58 pm
Quote:
Dolby has a new thing -- HDR LCD that on the fly
modulates the LED backlights for brightness in groups.
Which would be fine if the LEDs corresponded exactly
to the pixels. But they don't.
I've seen at least one review that complained that local dimming produced
"halos" around objects in darker scenes. I would never, ever buy a set with
such a feature, unless it could be shut off.
Guest
Fri Feb 26, 2010 5:46 pm
On Thu, 25 Feb 2010 15:47:16 -0800, "William Sommerwerck"
<grizzledgeezer_at_comcast.net>wrote:
Quote:
Ignoring the fact that colour displays are finely tuned
to the way that human colour vision works, and an alien
would likely wonder what we'd been smoking.
This has nothing whatever to do with color rendition.
Who is Sylvia, anyway?
A troll?
Guest
Fri Feb 26, 2010 5:47 pm
On Fri, 26 Feb 2010 12:13:47 +1100, "Phil Allison"
<phil_a_at_tpg.com.au>wrote:
Quote:
** And if you put the remark back into its context - what it IS relevant
to becomes obvious.;
No it doesn't.
Dave Plowman (News)
Guest
Fri Feb 26, 2010 5:49 pm
In article <hm8om0$o3m$1_at_speranza.aioe.org>,
bob urz <sound_at_inetnebr.com> wrote:
Quote:
It can get more complicated than that. Dolby has a new thing out HDR LCD
that on the fly modulates the LED backlights for brightness in groups.
that was not possible with CFL LCD backlights.
Which would be fine if the LEDs corresponded exactly to the pixels. But
they don't.
--
*A plateau is a high form of flattery*
Dave Plowman dave_at_davenoise.co.uk London SW
To e-mail, change noise into sound.
Guest
Fri Feb 26, 2010 5:51 pm
On Fri, 26 Feb 2010 02:32:38 -0000, "Arfa Daily"
<arfa.daily_at_ntlworld.com>wrote:
Quote:
"William Sommerwerck" <grizzledgeezer_at_comcast.net> wrote in message
news:hm7241$21g$1_at_news.eternal-september.org...
First, the only televisions that use LEDs use OLEDs. There are none using
conventional LEDs.
Second, there are no strict definitions of what these refresh rates mean.
In
some cases, the set generates an interpolated image at that rate, in
others,
a blank (black) raster is inserted. Some sets combine both.
I don't like this enhancement (which was one of the reasons I bought a
plasma set). It has a nasty side-effect -- it makes motion pictures look
like video. This might be fine for a TV show; it isn't when you're
watching
movies. Be sure that whatever set you purchase has some way of defeating
it
the enhancement.
You need to actually look at the sets you're considering with program
material you're familiar with.
Seconded on all counts, and also the reason that I recently bought a plasma
TV (Panasonic, 50" full HD panel, 400Hz). I have not seen a single thing
about this TV that I don't like so far, unlike the LCD TVs that I have in
the house, and the LCDs that cross my bench for repair, all of which suffer
from motion artifacts, scaling artifacts, and motion blur ...
This plasma TV has produced absolutely stunning HD pictures from the Winter
Olymics, with not the slightest sign of motion artifacts of any description,
even on the fastest content like downhill skiing, and bobsleigh etc. In
contrast, the same content that I have seen on LCDs, has been perfectly
dreadful.
Arfa
Maybe I'm not picky but those motion artifacts just aren't important
enough for me to want to spend thousands on something that doesn't
produce them. I have a fairly cheep 32" and while it does produce some
artifacts they are insignificant to the overall performance.
Arfa Daily
Guest
Fri Feb 26, 2010 6:04 pm
"William Sommerwerck" <grizzledgeezer_at_comcast.net> wrote in message
news:hm8g13$p9t$1_at_news.eternal-september.org...
Quote:
If you are seriously considering the purchase of a flatscreen TV of any
description, the best advice I can give you is to know what you're asking
and seeing in the showroom.
Yes, yes, yes, yes, yes.
Plasma panels also
do not suffer from any viewing angle issues, which can be a problem with
LCDs, particularly if you are thinking of wall-mounting, as most will
then
need to be angled down towards your sitting position.
Yes, but... I'm surprised at the wide viewing angles of many LCDs, even
close to the screen. It no longer seems to be a problem, unless the
mishpoche has gathered to watch.
Yes, agreed in general, but it does seem to depend a lot on how much you are
prepared to pay. The point I was making was that LCD screens tend to be
optimised for horizontal viewing angle, and with the supposition that you
will be looking directly at the screen, or even slightly down on it, when it
is sitting on a conventional lounge stand. When it is mounted on a wall, you
will be looking at it from below, and some LCDs - the one I have in my
kitchen, for instance - are not terribly good when viewed from such an
angle. I had to tilt mine down perhaps 10 degrees, after which, it was fine,
so I was just making the point that it's something else to consider *if* the
OP was going for an LCD, and *if* he had any intention of wall mounting it.
Quote:
You should also be aware that there are several 'resolutions' of screen
and
drive to take into consideration. Almost all TV showrooms both here and
in
the US, tend to have the sets running on at least an HD picture, and
often
a
BluRay picture. This makes them look very good at first glance. Problem
is
that in normal day to day use when you get it back home, you are going to
be
watching standard resolution terrestrial broadcasts on it, and on many
sets,
these look pretty dreadful, and it is the reason that so many people are
disappointed with their purchase when they get it home, and think that it
is
not what they saw in the store.
Yes and no. Most sets do a poor job upconverting 480i to 1080p, and the
result can be smeary. The solution is to get cable, with many programs
available at native resolutions of 720p or 1080i. The image quality can
equal Blu-ray.
Again, yes in principle. But not all sets are equal in this respect, and not
everyone has access to cable, so it was just one more aspect of the
purchasing problem, for the OP to be aware of. I have to say that the 480
upscaling on the Pan plas that I recently bought, is exceptionally good.
Although I have satellite here, with a good few genuine HD channels, I also
watch many SD sat channels, and SD terrestrial digital channels, and the
upscaling to display them on the full HD 1080 panel, is nothing short of
excellent.
Quote:
BluRay is a full HD source. This is handled fine by most sets, but be
aware
that if the TV is just HD compatible rather than "Full HD", then the
native
resolution of the actual display panel, will again not match the
resolution
of the signal, and downscaling will take place within the TV to make them
match.
It depends. I have a 32" 720p set in my den, and it has no trouble with
1080i signals.
Again, yes. Downscaling seems to be better handled than upscaling in terms
of artifact generation, even on the cheap-end TVs. Again, I was only making
the point in an effort to allow the OP to better understand what he needs to
be looking for, and asking about, to avoid disappointment with his purchase.
Quote:
So, if you are a film buff, and likely to watch stuff on BluRay, you
should
consider a set with a full HD panel resolution (1920 x 1080). If it's a
large screen you are wanting...
...and wanting it you will be...
...consider a plasma over an LCD. Whilst these are still more expensive
than
LCD, world recession has caused the prices of them to tumble over the
last
12 months, and Panasonic gives very long warranties with them.
"Home Entertainment" magazine gave a near-frothing-at-the-mouth review to
a
48" Panasonic plasma that goes for $1500.
I paid 699 UKP for my 50" Pan plas, so I guess that it's either the same or
a similar spec model to the one they reviewed. There are several variants
depending on features such as how many HDMI ports, and whether or not they
have a built-in sat tuner and so on, but all based on the same basic design.
I have to say that I would give it the same "frothing at the mouth" review
as your Home Entertainment mag. I spent a long long time looking into this,
as I knew that I was going to have a hard job replacing my large-screen Tosh
CRT - which produced superb pictures from all sources -with anything
flat-screen. I knew all along that it was a plas that I wanted really, but
didn't think that I was going to be able to afford one. Now that I've had it
a couple of months, there is absolutely nothing - and I really mean
nothing - that I could pick fault with, so if you are prepared to look long
and hard enough, it is possible to get what you want from this technology.
One other thing that the OP might consider, when he has arrived at a few
models that he might be interested in, is to see what he can find out about
those models by Googling them, and then looking to see what is being said
about them on forums. Many forums have contributors that are hyper-critical
and quite brutal with their comments, and I think that there is a lot to be
learned from trawling these forums. FWIW, before I actually bought my Pan, I
did exactly this, and to my utter surprise, there was barely a single
adverse comment world-wide. The only thing that was commented on by a few
people was that they thought that SD sources displayed on this set, were
perhaps a little 'soft' in terms of contrast, but personally, I didn't find
this either on the showroom model that was demo'd to me, or on the one that
I now actually have. This sort of thing is another reason to understand what
you are asking, and making sure that all these sources and features are
shown to you.
Quote:
One final point -- don't be overly impressed by the brightest set. Look
critically at the image, with a variety of material.
Yes, 100% agreed
Quote:
By the way, I've seen the Samsung "LED" set repeatedly at Fry's. I don't
like it. I can't quite put my finger on it, but it looks "garish". This
might be the way the sample was set up, or it might be inherent. If I were
buying an LCD set, it would probably be a Sony.
Yes, agreed on the LED backlit Sammy. I don't like it either, and like you,
can't quite put my finger on exactly why ... My mother owned a 37" Tosh
for a few months before she recently passed on, and that was as good as I
have seen in LCD. I think that if an LCD is the chosen route, it is better
to stick to the big far east names
Arfa
Quote:
William Sommerwerck
Guest
Fri Feb 26, 2010 7:15 pm
Quote:
** And if you put the remark back into its context --
what it IS relevant to becomes obvious.
No it doesn't.
Agreed. It seemed unrelated, even out of left field. I suspect Sylvia didn't
properly express what she wanted to say.
William Sommerwerck
Guest
Fri Feb 26, 2010 7:20 pm
Quote:
I don't know how a 240Hz "scan rate" would be achieved.
It's probably a sort of trick that the set's electronics use
to make the picture seem just that much more stable.
Actually, it's a frame rate. It can be done by interpolation, by inserting
blank frames, or a combination of the two.
AZ Nomad
Guest
Fri Feb 26, 2010 7:29 pm
On Fri, 26 Feb 2010 10:20:29 -0800, William Sommerwerck <grizzledgeezer_at_comcast.net> wrote:
Quote:
I don't know how a 240Hz "scan rate" would be achieved.
It's probably a sort of trick that the set's electronics use
to make the picture seem just that much more stable.
Actually, it's a frame rate. It can be done by interpolation, by inserting
blank frames, or a combination of the two.
or perhaps it's just a flash rate, the pulses powering the LED backlight
David Nebenzahl
Guest
Fri Feb 26, 2010 7:39 pm
On 2/26/2010 8:46 AM Meat Plow spake thus:
Quote:
On Thu, 25 Feb 2010 15:47:16 -0800, "William Sommerwerck"
grizzledgeezer_at_comcast.net>wrote:
Ignoring the fact that colour displays are finely tuned
to the way that human colour vision works, and an alien
would likely wonder what we'd been smoking.
This has nothing whatever to do with color rendition.
Who is Sylvia, anyway?
A troll?
Why would you jump to that conclusion?
Oh, forgot; that's what you do.
--
You were wrong, and I'm man enough to admit it.
- a Usenet "apology"
Guest
Fri Feb 26, 2010 7:51 pm
On Fri, 26 Feb 2010 10:15:56 -0800, "William Sommerwerck"
<grizzledgeezer_at_comcast.net>wrote:
Quote:
** And if you put the remark back into its context --
what it IS relevant to becomes obvious.
No it doesn't.
Agreed. It seemed unrelated, even out of left field. I suspect Sylvia didn't
properly express what she wanted to say.
You have your posting style. No big deal to me. Those who don't want
to read you have their choice to or not to.
William R. Walsh
Guest
Fri Feb 26, 2010 8:09 pm
Hi!
Quote:
Yes, that is how it was explained to me from a salesman as
well as what I gathered from online info. So, apparently, it is
still an LCD screen.
Yes, I'm sure it is. The only thing that's changed is the way the
panel is illuminated so you can see a picture. It used to be that
practically all LCD panels were backlight by a fluorescent tube (or a
set of tubes).
For a variety of reasons, this has changed. (These reasons would be
mercury in fluorescent tubes, lifetime of said tubes as compared to
LEDs, complexity of the driving electronics and energy efficiency.)
The "120Hz" refresh rate would not be hard to achieve. An interlaced
scanning method produces a picture that (in many cases) appears to
flicker much less than a non-interlaced one.
(IBM used to use a similar trick with their 8514 display. It used a
44Hz interlaced vertical scan rate that IBM called an "88Hz" scan
rate. It worked reasonably well, as long as you used an IBM monitor
with longer persistence phosphors and didn't have anything like a
fluorescent light fixture illuminating the room. If you did, the two
tended to "beat" against one another and the effect is annoying. And
if you didn't use an IBM monitor with the special phosphors, that
increased the apparent "flicker" level.)
I don't know how a 240Hz "scan rate" would be achieved. It's probably
a sort of trick that the set's electronics use to make the picture
seem just that much more stable.
William
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