> In the digital realm, anything capable of handling the signal should be as 
> good as any other,

Unless it is *only just* capable of handling the signal, in which case any 
additional interference (eg you put a new device or another cable next to 
the HDMI cable or receiver, a car drives past, someone turns on a motor, 
etc) and then it will stop working.  I have never seen anything like this 
though, even my $10 5 meter DVI->HDMI cable has worked flawlessy at 1080p 
while being tangled up behind 100 other cables behind my computer and TV.

> the higher bandwidth might be necesary.  But for now, what good is it?

It's always good to have a little in reserve, as explained above, but really 
I suspect the ultra cheap ones have plenty enough in reserve.  The shops 
that you go to of course are going to stock the expensive ones, as they 
would prefer to make $20 profit on an $80 cable than $2 on an $8 one. 
Magazine reviews are also biased because the makers of the $100 cables send 
them loads for free, if the magazine writes bad reviews about them being a 
waste of money they likely will not get any more.

> In fact, I'm still not convinced that 120Hz LCD makes any sense 
> whatsoever.  With CRT's, it made a LOT of difference, because it 
> substantially reduced flicker.  LCD doesn't have flicker.  It has response 
> times, and lowering the response times does make a difference.  I'm not 
> convinced that a 5ms 60Hz screen would be any different from a 5ms 120Hz 
> screen, or even a 5ms 240Hz screen.

When your eye tracks a moving object on an LCD you see blur for two reasons. 
One is the response time of the pixel, the other is the fact that the LCD is 
finite resolution and the frames are displayed continuously (and not as 
impulses like a CRT).  Even with a response time of 0ms you will still see 
image blur.

Recently the LC technology has improved giving faster switching times.  This 
has two impacts, it means the 2nd type of blur I mentioned above becomes 
more apparent, and that it's possible to refresh at higher than 60 Hz.

Given the very fast response time, the easiest easiest way to reduce blur is 
to simply show a totally black frame between each real frame.  In theory you 
could make an LCD perform like a CRT by only showing the frame for the first 
5-10% of the frame, then showing black for the rest of it.  Recently with 
LED backlights it is becoming very easy to do this sort of thing (LEDs don't 
care if they are at 100% brightness 100% of the time, or 1000% brightness 
for 10% of the time).

As already mentioned, it makes an even better effect if the TV can 
intelligently calculate some "inbetween" frames to display.  This has the 
disadvantage of being costly to implement and obviously not being able to 
predict everything perfectly.  But mostly the result is visually superior to 
simple black frame insertion.

BTW I would suggest comparing fast scrolling text (eg end credits of a TV 
show) on a normal TV and a 120 / 240 Hz version - the difference is obvious.

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> Yes. OTOH the digital signal fails fully when it fails, with analog
> signal you're still able to get the information from the news with even
> very bad signal (while you don't want to see a movie with such signal).

I wonder if you transmitted analogue at the power where digital starts to 
fail, what the analogue picture would look like?  Where my mum lives they 
still transmit both, the analogue TV is transmitted at 500 kW and the 
digital at 20 kW...

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> It just puzzles me that if they were going to make everything incompatible 
> so they could up the resolution, why didn't they up it to something really 
> high? You know, so you can *see* a difference?

If you can't tell the difference between SD and HD (because your TV is too 
small and/or you're too far away from it) then you *certainly* are not going 
to notice any difference with an even higher resolution.

Currently I doubt many people would want a large enough TV, or sit close 
enough to it, to warrant much higher than 1920x1080.

What would be an improvement is to start recording at a higher frame rate, 
120 Hz would do nicely (I have very fond memories of playing some games at 
120 Hz on my old CRT, the smoothness was awesome).

Post a reply to this message

Neeum Zawan wrote:

> 	What movie? If it's more than 5 years old, don't expect too much of a
> difference.

Demons & Angels. Came in the box with the player.

I also started watching the last Harry Potter film.

>> Now I've got Harry Potter and the Half-Blood Prince. The box contains
>> the exact same film on BD and DVD, so I can actually compare like for
>> like. But I haven't done so yet.
> 
> 	That should show it.

I've watched at least half the film in HD. Haven't tried it in SD yet.

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scott wrote:

> What would be an improvement is to start recording at a higher frame 
> rate.

Yeah, that too. Wasn't 24 FPS chosen because it's the *minimum* frame 
rate that yields a believable illusion of motion?

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>> What would be an improvement is to start recording at a higher frame 
>> rate.
>
> Yeah, that too. Wasn't 24 FPS chosen because it's the *minimum* frame rate 
> that yields a believable illusion of motion?

Yup, IIRC the maximum (ie above that you don't really notice any difference) 
is somewhere around 100 Hz.

I wonder how long before LCD makers start marketing their high framerate TV 
technology in computer monitors?  The hard core gamers should like it.

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And lo On Sun, 07 Mar 2010 03:31:50 -0000, UncleHoot
<jer### [at] mutualdatacom> did spake thusly:

> "Neeum Zawan" <m.n### [at] ieeeorg> wrote in message  
> news:4b9297f6$1@news.povray.org...
>> On 03/06/10 02:24, Orchid XP v8 wrote:
>>> I've only seen HD stuff in shops, but from what I can tell, there's no
>>> visible difference between HD and SD. If I ever get time to set up my
>>> mum's new BluRay player, maybe I can test for myself. But seriously,
>>> everybody's going on like it fundamentally transforms your viewing
>>> experience. But it's only 4x the resolution. Not 40x or 400x, just 4x.
>>> And, from what I've seen, this equals to a slight increase in  
>>> constrast,
>>> and not much else.
>>
>> Woah! There's a *big* difference in quality. Try playing 1080p content
>> if your TV can handle it. If not, even 720p should be noticeable. Many
>> stores I've been to just show trash.
>
> Agreed.  The stores suck.    And the difference in quality is huge.   
> Anyone who doesn’t see the difference should switch back to a 640x480  
> interlaced analog monitor.  ;-)

Unless it's a dedicated stand I've yet to see an HD television receive an
HD signal in-store. They're either using a splitter through the standard
aerial port or composite cables, or they're broadcasting the over-the-air
Freeview channels which are all SD.

Just to go off-topic here-in lies another joyous thing in the UK - 'We're
switching off the analogue broadcasts you'll need a digital receiver'. So
off everyone goes to buy either a new television or set-top box. Now it's
- 'We're cutting some of the Freeview channels down to be able to
broadcast HD' Fair enough - 'We'll be using mpeg4 rather than mpeg2 so
pretty much none of the set-top boxes/digital televisions you've bought
will work with it; go and buy a new one'.

Okay back on-topic, the settings on the television also make a difference.
On mine I had to turn the sharpening off with SD broadcasts; terrible  
fringing.

-- 
Phil Cook

--
I once tried to be apathetic, but I just couldn't be bothered
http://flipc.blogspot.com

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Phil Cook v2 wrote:

> Just to go off-topic here-in lies another joyous thing in the UK - 'We're
> switching off the analogue broadcasts you'll need a digital receiver'. So
> off everyone goes to buy either a new television or set-top box. Now it's
> - 'We're cutting some of the Freeview channels down to be able to
> broadcast HD' Fair enough - 'We'll be using mpeg4 rather than mpeg2 so
> pretty much none of the set-top boxes/digital televisions you've bought
> will work with it; go and buy a new one'.

Wait... what? That's news! o_O

Post a reply to this message

And lo On Mon, 08 Mar 2010 09:05:13 -0000, Invisible <voi### [at] devnull> did  
spake thusly:

> Neeum Zawan wrote:
>
>> 	What movie? If it's more than 5 years old, don't expect too much of a
>> difference.
>
> Demons & Angels. Came in the box with the player.
>
> I also started watching the last Harry Potter film.
>
>>> Now I've got Harry Potter and the Half-Blood Prince. The box contains
>>> the exact same film on BD and DVD, so I can actually compare like for
>>> like. But I haven't done so yet.
>>  	That should show it.
>
> I've watched at least half the film in HD. Haven't tried it in SD yet.

I've watched both the Harry Potter and Batman Begins in both DVD and HD.  
In fact I slotted in BB DVD into my PS3 while running BB Blu-ray on my  
dedicated player. Skipped through to Bruce Wayne picking the flower,  
paused it and jumped between inputs. You could tell easily which was  
which. Likewise in some of the darker sections, much less noise on the  
Blu-ray version.

-- 
Phil Cook

--
I once tried to be apathetic, but I just couldn't be bothered
http://flipc.blogspot.com

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Nicolas Alvarez wrote:
> Orchid XP v8 wrote:
>> (And that of course is the other undesirable thing about digital TV.
>> There used to be, like, 5 channels, 4 of them containing high quality
>> programming. Now there's 500 channels and they're *all* showing utter
>> crap that nobody would ever want to watch...)
> 
> That has nothing to do with digital TV. It's just the drop of quality 
> programming happened at the same time. Correlation != causation.

The increase in available channels isn't related to the decrease in 
signal bandwidth per channel due to being digital?

-- 
http://blog.orphi.me.uk/
http://www.zazzle.com/MathematicalOrchid*

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