SD pictures on HD TV

I keep seeing people saying
'My new TV a ?????ashuie? gives a good picture on SD from my sky box+ HD.
HD Freeview. etc etc.

They never qualify this by specifying if the Box is set to output 1080 or
720 or real SD.

Do they realise that if the box is up scaling then the SD picture they are
looking at is not due to their TV but to the Box.

Just a thought

Gary

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On 28/09/2010 12:47, Gary wrote:
I keep seeing people saying
'My new TV a ?????ashuie? gives a good picture on SD from my sky box+
HD. HD Freeview. etc etc.

They never qualify this by specifying if the Box is set to output 1080
or 720 or real SD.

Do they realise that if the box is up scaling then the SD picture they
are looking at is not due to their TV but to the Box.

Just a thought

Gary


The (Samsung) Sky+HD box by default outputs at 1080i, and gets the
aspect ratio wrong (on my Sony 32" 720p set) half of the time. Setting
the sky box to output in the broadcast format lets the tv do the scaling
properly, and if that gets the aspect ratio wrong at least the zoom /
stretch / squash button on the tv remote works (doesn't work with a 1080
signal). Reckon a lot of people will leave the sky hd box on defaults
and ignore the stretchyvision, assuming my Sony tv isn't unusual in this
behaviour.

(I've not got an HD subscription, btw. Wouldn't be worth it at all on
the 32" 720p set viewed from a reasonable distance.)

Dominic.

Dominic wrote:

Reckon a lot of people will leave the sky hd box on defaults
and ignore the stretchyvision

That's what they all did with SD, so I guess you're right.

I can't count the number of people's SKY boxes where I've corrected the
aspect ratio settings (and enabled RGB instead of composite) only to
find next time I've visited they've put them back to stretchyvision.

Andy Burns wrote:
Dominic wrote:

Reckon a lot of people will leave the sky hd box on defaults
and ignore the stretchyvision

That's what they all did with SD, so I guess you're right.

I can't count the number of people's SKY boxes where I've corrected the
aspect ratio settings (and enabled RGB instead of composite) only to
find next time I've visited they've put them back to stretchyvision.

Same here. The mother in law even phoned me after the last visit where I'd
stuck her TV back to auto switch between 4:3 and 16:9, to say some of her
channels were, quote; 'all narrow'.

I despair !!

--
Mark
Please replace invalid and invalid with gmx and net to reply.

www.paras.org.uk

On Sep 28, 8:23*pm, Mark Carver wrote:
Andy Burns wrote:
Dominic wrote:

Reckon a lot of people will leave the sky hd box on defaults
and ignore the stretchyvision

That's what they all did with SD, so I guess you're right.

I can't count the number of people's SKY boxes where I've corrected the
aspect ratio settings (and enabled RGB instead of composite) only to
find next time I've visited they've put them back to stretchyvision.

Same here. The mother in law even phoned me after the last visit where I'd
stuck her TV back to auto switch between 4:3 and 16:9, to say some of her
channels were, quote; 'all narrow'.

I despair !!

--
Mark
Please replace invalid and invalid with gmx and net to reply.

www.paras.org.uk

Same here, the rest of the household moan like hell when I set the TV
to autoswitch properly, personally I'm baffled as to how
stretchyvision can be considered 'normal' but there ya go.

"Gary" wrote in message
...
I keep seeing people saying
'My new TV a ?????ashuie? gives a good picture on SD from my sky box+ HD. HD
Freeview. etc etc.

They never qualify this by specifying if the Box is set to output 1080 or 720
or real SD.

Do they realise that if the box is up scaling then the SD picture they are
looking at is not due to their TV but to the Box.

In the case of SkyHD boxes, you can't watch interlaced SD via HDMI without the
box processing and re-scaling it.
With HDMI output set to "Auto", it sends SD content to the TV as 576p. 50i
source material is poorly deinterlaced by the box itself; a process which
involves (amongst other things) it being re-scaled to 576 progressive 50fps,
only to be re-scaled once again when it reaches the TV.

25fps "filmic effect" SD content with 2:2 pulldown does seem to be detected by
the SkyHD box however, and each frame sent to the TV twice with both fields
unmodified (as it should be if you're using 576p). Presumably it also ensures
the correct pairs of fields are sent together in each newly-generated frame.

jamie.
--

"Mark Carver" wrote in message
...
Andy Burns wrote:
Dominic wrote:

Reckon a lot of people will leave the sky hd box on defaults
and ignore the stretchyvision

That's what they all did with SD, so I guess you're right.

I can't count the number of people's SKY boxes where I've corrected the
aspect ratio settings (and enabled RGB instead of composite) only to find
next time I've visited they've put them back to stretchyvision.

Same here. The mother in law even phoned me after the last visit where I'd
stuck her TV back to auto switch between 4:3 and 16:9, to say some of her
channels were, quote; 'all narrow'.

I despair !!

--
Mark
Please replace invalid and invalid with gmx and net to reply.

www.paras.org.uk

Some people believe anything is better if it's advertised as better.

Personally I hate the fact that the introduction of wide screen means I'm
expected to either crop the tops and bottoms off or watched a stretched
picture for 4:3 material. Our current Philips (spit) LCD TV's manual says
not to use letter box mode, presumably because the LCD might burn in so that
in wide screen you see two faint lines where the 4:3 image would end.
Personally I'd take that chance but the others in the house won't

Two of our Freeview boxes don't even allow the option of letterboxing if you
tell them you have a wide screen TV.

--

Brian Gregory. (In the UK)

To email me remove the letter vee.

Brian Gregory [UK] wrote:

Two of our Freeview boxes don't even allow the option of letterboxing if
you tell them you have a wide screen TV.

You don't mean letterboxing, do you? I thought that was for viewing
widescreen material on a 4:3 screen (or Cinemascope on 16:9).

By the way, I don't think there's any real chance of image burn-in on
an LCD, is there? Plasmas, yes, but LCD?

Maybe once upon a time, but not nowadays, surely.

SteveT

On Wed, 29 Sep 2010 20:42:34 +0100, Steve Thackery
wrote:

Brian Gregory [UK] wrote:

Two of our Freeview boxes don't even allow the option of letterboxing if
you tell them you have a wide screen TV.

You don't mean letterboxing, do you? I thought that was for viewing
widescreen material on a 4:3 screen (or Cinemascope on 16:9).

By the way, I don't think there's any real chance of image burn-in on
an LCD, is there? Plasmas, yes, but LCD?

Maybe once upon a time, but not nowadays, surely.

It isn't burn-in. It is called "image retention", "image persistence" or
"image sticking" when it happens on LCDs.

It can be corrected.
These explain (I can't confirm the accuracy):
http://www.practical-home-theater-gu...-sticking.html

Image sticking is an intrinsic behavior of TFT LCD
panels. It is the result of their susceptibility to polarization of
the liquid crystals inside the display panel when a static image
remains displayed on the screen for too long.

This results in a parasitic charge build-up, or polarization, within
individual pixels and sub-pixels. This polarization takes place at
the liquid crystal level in the LCD panel; it affects the crystals'
optical properties as it prevents the liquid crystals to return
fully to their normal 'relaxed' state upon deactivation.
....
....
Unlike permanent burn-in in phosphor-based displays, which is the
result of a premature aging of the phosphors of individual pixels,
and thus, is irreversible, image sticking in LCD panels can often be
reversed to a point of total invisibility.

However, the extent to which image sticking can be reversed depends
on the severity of the causes that eventually led
to image retention; top in the list is the environmental temperature
at which image sticking took place.

A way to remove a retained image on an LCD panel is to run an
all-white screen saver for several hours. It would generally help to
run this image sticking reversal operation at an elevated
temperature of around 100 deg. Fahrenheit or 40 deg. Celsius. This
should help speed up the reversal process.

Some manufactures recommend using an all-back or dark gray pattern
screen saver instead of an all white screen. Whichever method you
choose, make sure the LCD TV or monitor energy savings settings will
not turn the backlight off after some time of inactivity.

Other manufacturers recommend turning off the LCD display for a
longer period than the time it took for the static image to cause
image retention.

While all three methods can help remove image sticking, yet our best
advice is to follow the manufacturer's instructions - if available.

http://www.lcdtvreviews.org.uk/lcd-t...-be-corrected/

Corrective measures
Image persistence ... can be rectified using following methods:

* If a image persists on your LCD screen, you may keep your LCD
screen unused for hours together. If it still persists, turn it off
for a few weeks. Often it enables your LCD screen to correct the
problem itself.

* Any graphical image used as screen saver often helps to remove the
image persistence if it is kept rotating over the screen for longer
periods.

--
Peter Duncanson
(in uk.tech.digital-tv)

In article ,
Steve Thackery wrote:
Brian Gregory [UK] wrote:

Two of our Freeview boxes don't even allow the option of letterboxing
if you tell them you have a wide screen TV.

You don't mean letterboxing, do you? I thought that was for viewing
widescreen material on a 4:3 screen (or Cinemascope on 16:9).

By the way, I don't think there's any real chance of image burn-in on
an LCD, is there? Plasmas, yes, but LCD?

It's there on a reasonably new monitor in our theatre on the lighting esk.

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