1080p vs 1080i

"Eddie G" wrote in message
. ..


This is what I thought after my post. So there is no reason to buy a
1080p
TV or worry about a home theater receiver that has 1080i vs 1080p for it's
HDMI interface? Will there be a reason for 1080p in the near future, or
should I get a 1080i set and not worry about it?




to view a 1080i picture to it's full potential you want a 1080p display.
you also want one if you plan to ever watch blu ray or hd dvd movies - which
are 1080p.


--
Gareth.

That fly... is your magic wand.
http://www.last.fm/user/dsbmusic/

On Oct 6, 3:34 am, "the dog from that film you saw"
wrote:
"Eddie G" wrote in message

. ..

This is what I thought after my post. So there is no reason to buy a
1080p
TV or worry about a home theater receiver that has 1080i vs 1080p for it's
HDMI interface? Will there be a reason for 1080p in the near future, or
should I get a 1080i set and not worry about it?

to view a 1080i picture to it's full potential you want a 1080p display.
you also want one if you plan to ever watch blu ray or hd dvd movies - which
are 1080p.

This is my last question on this...

If the TV is 1080p does it matter if the receiver has HDMI 1080i or
1080p? My first thought is I would want a receiver that has 1080p
HDMI, but then now I am thinking it is the TV and the receiver is just
relaying the signal from the cable box.

Am I correct in my thinking?

On Sat, 06 Oct 2007 05:39:20 -0700, Eddie G wrote:

On Oct 6, 3:34 am, "the dog from that film you saw"
wrote:
"Eddie G" wrote in message

. ..

This is what I thought after my post. So there is no reason to buy a
1080p
TV or worry about a home theater receiver that has 1080i vs 1080p for it's
HDMI interface? Will there be a reason for 1080p in the near future, or
should I get a 1080i set and not worry about it?

to view a 1080i picture to it's full potential you want a 1080p display.
you also want one if you plan to ever watch blu ray or hd dvd movies - which
are 1080p.

I'm not saying you're wrong, but I disagree on this. If the source is
1080i, the TV will convert it to 1080p, but the picture won't be
improved. I might argue that you may get a slightly degraded picture
since the TV is having to convert to 1080p, rather than a 1080i TV
simply showing the picture in its native format.

This gets REALLY academic, though, as a 1080i, 720p, or 1080p picture
is going to look terrific no matter what the native resolution is.

I would also not advise making a decision based on side-by-side
comparisons at a store such as Best Buy. The settings on those sets
are not optimized for home viewing.

This is my last question on this...

If the TV is 1080p does it matter if the receiver has HDMI 1080i or
1080p? My first thought is I would want a receiver that has 1080p
HDMI, but then now I am thinking it is the TV and the receiver is just
relaying the signal from the cable box.

Am I correct in my thinking?


Yes, if the source component is 1080p (HD-DVD, Blu-Ray, etc.) as
you'll want the receiver to pass on the 1080p to get the best picture.
However, a quick check on Crutchfield is showing all of their
HDMI-compatible receivers to be 1080p, so this is probably a
non-issue. Make sure you pay attention to things such as audio
pass-through, as some receivers require a separate audio cable.

Good luck.

"kjw" wrote in message
...


to view a 1080i picture to it's full potential you want a 1080p display.
you also want one if you plan to ever watch blu ray or hd dvd movies -
which
are 1080p.

I'm not saying you're wrong, but I disagree on this. If the source is
1080i, the TV will convert it to 1080p, but the picture won't be
improved. I might argue that you may get a slightly degraded picture
since the TV is having to convert to 1080p, rather than a 1080i TV
simply showing the picture in its native format.




i was talking from a 'buying a plasma/ lcd screen' point of view - of course
if you buy a regular crt HDTV then 1080i is fine - you wont get a native
1080i plasma/lcd.unless i'm being really dumb.




--
Gareth.

That fly... is your magic wand.
http://www.last.fm/user/dsbmusic/

On Sat, 06 Oct 2007 02:40:14 GMT Alan F wrote:
| Eddie G wrote:
| On Oct 5, 3:23 pm, wrote:
| Is it correct to say that both have the same spatial resolutions, but
| each pixel in the picture is refreshed at a different rate b/w the two
| formats?
|
| In theory, the higher the update rate the better (this is not hard to
| understand). But there has to be a threshold, due to physiology of
| human vision, beyond which point it doesn't matter anymore.
|
| Is 30Hz not enough to "fool" human eyes?
|
| I want to go to a store and have them set up 2 of the same tv's and
| have one signal at 1080p and another at 1080i so I can see the
| difference. Is Comcast transmitting in 1080p? The store would have
| to have a 1080p signal, though...
|
| Are the HD dvd's 1080i or 1080p?
|
| Thanks!
|
| Eddie G
|
| No one broadcasts at 1080/60p or even at 1080/24p (which is one of the
| 18 ATSC standard formats). The only common source for that is going to
| be a computer generated video or 1080/60p video which is high end
| equipment at this point.

The major broadcast networks in the US do not use 1080p24, that's for
sure. But their content isn't "movies all day", either. If it were,
then 1080p24, or 720p24, or even 480p24 (depending on how many channels
they want to try to squeeze in), would make sense.


| The issue is the source. Is it film shot at 24 fps or video cameras at
| 50i (Europe) or 60i? Comparing 1080p versus 1080i is not a simple thing
| to do.
|
| The movies on HD-DVDs which were shot on film are stored at 24p.
| Sources from video cameras might be different - 50i, 60i, 30p, whatever.
| The earlier HD-DVD players could only output up to 1080/60i, the most
| recent generation nows provides for a 1080/24p output. Not sure if they
| support 1080/60p yet, but then most TVs up to this year didn't either.

I'm glad to see support for 24 fps being added to LCD TVs and monitors.
I hope this works its way down to computer monitors, too.


| Because almost flat panel and RP TV based on LCD, DLP, SXRD/D-ILA/LCOS
| TVs are inherently progressive displays, the stores and TV manufacturers
| push 1080p as if it were the greatest thing since sliced bread. The fact
| that most HD channels are 1080i just confuses people.

True, the stores, as well as manufacturer marketing, are a good bit short
of being honest about it all. But 1080p is better to have if you might be
using any source that could have 1080p, or upconvert to 1080p. Otherwise
the existance of 1080p could indicate greater processing power that could
do a better job dealing with other format sources, including interpolating
interlaced sources. One sad fact is that stores do not demonstrate how
well a given set behaves on a variety of sources (OTA TV, cable, satellite,
DVD, high def DVD, computer analog, computer DVI). They just want to show
off that the set dazzles, which unfortunately most consumers fall for.

--
|---------------------------------------/----------------------------------|
| Phil Howard KA9WGN (ka9wgn.ham.org) / Do not send to the address below |
| first name lower case at ipal.net / |
|------------------------------------/-------------------------------------|

On Sat, 6 Oct 2007 08:34:56 +0100 the dog from that film you saw wrote:
|
| "Eddie G" wrote in message
| . ..
|
|
| This is what I thought after my post. So there is no reason to buy a
| 1080p
| TV or worry about a home theater receiver that has 1080i vs 1080p for it's
| HDMI interface? Will there be a reason for 1080p in the near future, or
| should I get a 1080i set and not worry about it?
|
|
|
|
| to view a 1080i picture to it's full potential you want a 1080p display.
| you also want one if you plan to ever watch blu ray or hd dvd movies - which
| are 1080p.

1080p60? or 1080p24?

I sure hope someone isn't upconverting p24 to p60.

--
|---------------------------------------/----------------------------------|
| Phil Howard KA9WGN (ka9wgn.ham.org) / Do not send to the address below |
| first name lower case at ipal.net / |
|------------------------------------/-------------------------------------|

wrote in message
...



| to view a 1080i picture to it's full potential you want a 1080p display.
| you also want one if you plan to ever watch blu ray or hd dvd movies -
which
| are 1080p.

1080p60? or 1080p24?

I sure hope someone isn't upconverting p24 to p60.




the films are on the disc as 24fps - although not all players - or indeed
screens, will co-operate with that.
so best to buy one that does.



--
Gareth.

That fly... is your magic wand.
http://www.last.fm/user/dsbmusic/

On Sat, 06 Oct 2007 14:24:47 GMT kjw wrote:
| On Sat, 06 Oct 2007 05:39:20 -0700, Eddie G wrote:
|
|On Oct 6, 3:34 am, "the dog from that film you saw"
wrote:
| "Eddie G" wrote in message
|
| . ..
|
| This is what I thought after my post. So there is no reason to buy a
| 1080p
| TV or worry about a home theater receiver that has 1080i vs 1080p for it's
| HDMI interface? Will there be a reason for 1080p in the near future, or
| should I get a 1080i set and not worry about it?
|
| to view a 1080i picture to it's full potential you want a 1080p display.
| you also want one if you plan to ever watch blu ray or hd dvd movies - which
| are 1080p.
|
| I'm not saying you're wrong, but I disagree on this. If the source is
| 1080i, the TV will convert it to 1080p, but the picture won't be
| improved. I might argue that you may get a slightly degraded picture
| since the TV is having to convert to 1080p, rather than a 1080i TV
| simply showing the picture in its native format.

If the native resolution is 1080, then it shouldn't matter, at least for
LCD. If the LCD pixel cells are updated exactly when their corresponding
line information arrives, it won't really be any different than if the
set stored the whole image in a buffer and drove the LCD to update all
the lines to be updated, which would have no effect on pixels that do
not change (which will be at least half of them all the time). The
issue is when when you have to _convert_ an interlaced source to some
other format. There is no 720i, so the only concerns are how to display
1080i and how to upconvert 480i. You can't avoid the issues of interlace
with the 480i. For 1080i you could just update pixels as they arrive.
Or you could have an interpolator that figures out what kind of motion
has happened since the previous field or two by comparing lines between
fields, then interpolating the missing lines by either choosing more of
the line in the previous field (less motion) or more of the lines above
and below it (more motion). That can make 1080i look smoother even if
less technically accurate.

if the native resolution is less than 1080 (768 or 900 is common), then
you have more issues in converting the interlace.


| This gets REALLY academic, though, as a 1080i, 720p, or 1080p picture
| is going to look terrific no matter what the native resolution is.

Better than 480i.


| I would also not advise making a decision based on side-by-side
| comparisons at a store such as Best Buy. The settings on those sets
| are not optimized for home viewing.

Nor do they show a variety of input sources. Set A could be better
than set B for 1080p coming in on HDMI, while set B could be better
than set A for 1080i coming in on cable ready QAM.

Choosing an HD set is hard. Technical specs don't cover all issues.
Stores don't let you see all source types in a viewing environment
that matches how you would use it at home (your lighting, your viewing
distances and angles).

You are probably better off visiting friends and neighbors that already
have an HD set and have similar viewing habits.


| Yes, if the source component is 1080p (HD-DVD, Blu-Ray, etc.) as
| you'll want the receiver to pass on the 1080p to get the best picture.
| However, a quick check on Crutchfield is showing all of their
| HDMI-compatible receivers to be 1080p, so this is probably a
| non-issue. Make sure you pay attention to things such as audio
| pass-through, as some receivers require a separate audio cable.

Is that 1080p23.976, 1080p24, 1080p29.97, 1080p30, 1080p59.94, or 1080p60?

--
|---------------------------------------/----------------------------------|
| Phil Howard KA9WGN (ka9wgn.ham.org) / Do not send to the address below |
| first name lower case at ipal.net / |
|------------------------------------/-------------------------------------|

On Sun, 7 Oct 2007 16:47:13 +0100 the dog from that film you saw wrote:
|
| wrote in message
| ...
|
|
|
| | to view a 1080i picture to it's full potential you want a 1080p display.
| | you also want one if you plan to ever watch blu ray or hd dvd movies -
| which
| | are 1080p.
|
| 1080p60? or 1080p24?
|
| I sure hope someone isn't upconverting p24 to p60.
|
|
|
|
| the films are on the disc as 24fps - although not all players - or indeed
| screens, will co-operate with that.
| so best to buy one that does.

Right. The problem is, the readily available tech specs don't have enough
detail to really tell.

One big problem is so many manufacturers have poorly designed web sites.
I was just at the Sharp web site today. I go to the LCD monitor section.
There are 3 subclasses of LCD monitors shown and a link for each. Two of
them that look like what I might want go to search pages. Well, there is
a menu on the left side so I expand that. It lists a LOT of model numbers
but not information any any (unless you click). So I'd have to click on
dozens of different links to sift through to find what I want, even if
they did provide the right technical data. But it just wasn't worth it
at that point, so I bailed out.

Apparently these companies only hire low end web designers.

--
|---------------------------------------/----------------------------------|
| Phil Howard KA9WGN (ka9wgn.ham.org) / Do not send to the address below |
| first name lower case at ipal.net / |
|------------------------------------/-------------------------------------|

wrote in message
oups.com...
Is it correct to say that both have the same spatial resolutions, but
each pixel in the picture is refreshed at a different rate b/w the two
formats?

Yes and no. First, for a still source image, yes, they should have the same
spatial resolution. But once the image is moving, the interlace degrades the
1080i image. It basically becomes a choice between annoying interlace
artifacts (comb patterns, etc.), or reducing the resolution by half (or some
combination thereof, with the persistent presence of filtering meaning that
even static scenes generally won't be as sharp in 1080i). Given that most of
the time only parts of the image are moving and that our eyes don't always
track moving objects that clearly anyway, 1080i ends up much better than
half as good as 1080p most of the time, but it's still not as good.

As for refresh rate, they're both 60Hz, so they can both reflect fast
changes well. It's just that the interlaced signal has those artifacts
(and/or reduced resolution).

In theory, the higher the update rate the better (this is not hard to
understand). But there has to be a threshold, due to physiology of
human vision, beyond which point it doesn't matter anymore.

Agreed. Though I suspect that figure is probably closer to the 60-120Hz
range than to 30Hz. (It certainly is when it comes to detecting flicker.)

Is 30Hz not enough to "fool" human eyes?

Generally, it's plenty fast enough to fool us into perceiving relatively
smooth motion, rather than a series of still images. (Even 15-25 fps is
often sufficient for that.) But that doesn't mean there is no improvement to
be had by going faster. It does depend on the source material, though - not
only that it does no good unless the source is faster also, but also that
fast motion (a wildly panning camera, etc.) will show the differences far
better than most average TV or movie material, which is relatively static or
at least doesn't usually move TOO fast if they want the viewer to be able to
follow it. (This should not be surprising, since it's almost all filmed at
either 24fps or 60Hz interlaced, and minimizing fast movement is desirable
for either situation, though for different reasons. Thus, cinematographers
are very aware of the framerate limitations of their medium, and plan their
shots accordingly.)

As for the possible advantages of a 1080p display, it's obvious that it
would be better for displaying any 1080 material than a 720p (or therabouts)
display, due to superior resolution. And that it would be superior to a
1080i display on any 1080p source material (at least on 1080p60, which
hardly exists, though probably a bit better on 1080p 24 as well). But it can
also improve the appearance of 1080i signals if good deinterlacing is used,
and can also fully show 720p signals with good upscaling in a way that a
1080i display can't. (At some point, a 1080i display essentially has to
throw away half the lines of a 720p signal, whether before or after
upscaling.)