More on 720 vs 1080, plasma

I'm leaning toward a 42" plasma.

There is a lot to know about 720p vs. 1080p and I've read alot,
understood some.

I know that most don't broadcast in 1080p anyway.

Here's some questions.

1. What is the 720 vs 1080 thing anyway. Lines? Lines per linear
inch? Lines of "resolution"? It seems like there would be more than
720 lines on a TV screen. That's only about 20 per inch for a 40 inch
set. I know, stupid, stupid question. Believe it or not, they don't
really mention it.

2. Some say you "can't tell the difference even if looking at 1080p
source" from 8-10 feet away if your set is under 46 or 50 inches.

Do you agree? Why would that be true? I would think, if it's lines
per inch that it wouldn't matter how big the set is.

3. this one only has 2 hdmi inputs. I guess one from satellite or
cable....and another one. Is that enough?

Sorry to ask simple probably redundant questions. Thanks for input
or opinions.

On 2007-12-27, kpb wrote:

1. What is the 720 vs 1080 thing anyway.

It's the signal resolution in pixels. The HDTV standard supports 1280x720 and
1920x1080. Actual TV displays may be different than these values.

2. Some say you "can't tell the difference even if looking at 1080p
source" from 8-10 feet away if your set is under 46 or 50 inches.

Do you agree? Why would that be true?

The eye has limited resolving power. Once you back off far enough that you
can't see individual pixels, there is no point in making them any smaller. How
small the pixels are depends on the native resolution of the display, the
screen size, and how far from it you are.

See the charts he http://www.carltonbale.com/blog/2006...p-does-matter/

3. this one only has 2 hdmi inputs. I guess one from satellite or
cable....and another one. Is that enough?

If you need more you can always get an HDMI switchbox.

-Bill
--
Sattre Press The King in Yellow
http://sattre-press.com/ by Robert W. Chambers
http://sattre-press.com/kiy.html

Bill McClain wrote:
On 2007-12-27, kpb wrote:

1. What is the 720 vs 1080 thing anyway.

It's the signal resolution in pixels. The HDTV standard supports 1280x720 and
1920x1080. Actual TV displays may be different than these values.

2. Some say you "can't tell the difference even if looking at 1080p
source" from 8-10 feet away if your set is under 46 or 50 inches.

Do you agree? Why would that be true?

The eye has limited resolving power. Once you back off far enough that you
can't see individual pixels, there is no point in making them any smaller. How
small the pixels are depends on the native resolution of the display, the
screen size, and how far from it you are.

See the charts he http://www.carltonbale.com/blog/2006...p-does-matter/

3. this one only has 2 hdmi inputs. I guess one from satellite or
cable....and another one. Is that enough?

If you need more you can always get an HDMI switchbox.

-Bill

Above all, choose a set by viewing the sort of
content (sports, studio, films etc.) you will
view most from the sources (OTA, DVD, Cable,
etc.) you'll use.

The chart Bill referenced looks "right-on" to my
eye. We have a new 1080p and an older 576p and
those seem to square with the chart.

We find that our 1080p set does a better job on
fast action sports from 720p sources (ESPN, Fox,
ABC) than it does converting 1080i sports
content from CBS or NBC. (Supporting the idea
that there's as much or more importance in
processing than than there is in the native
display.)

YMMV if you do all the format conversions in a
satellite box, a cable box or in a DVD player.

Three HDMI inputs would be nice. Our 1080p set
has only two (one is connected to a
switchbox). The switchbox wouldn't pass HDCP
codes from a Philips player or from our cable box.

We had to use component outputs from the player
and accept the resolution hit.

I dislike blunt assertions but, HDCP sucks!

--
pj

On Thu, 27 Dec 2007 06:57:49 -0800 (PST), kpb
wrote:

I'm leaning toward a 42" plasma.

Don't bump your nose!


There is a lot to know about 720p vs. 1080p and I've read alot,
understood some.

I know that most don't broadcast in 1080p anyway.

Right.


Here's some questions.

1. What is the 720 vs 1080 thing anyway. Lines? Lines per linear
inch? Lines of "resolution"? It seems like there would be more than
720 lines on a TV screen. That's only about 20 per inch for a 40 inch
set. I know, stupid, stupid question. Believe it or not, they don't
really mention it.

It's two things.

It's the signal. Some digital/HD broadcast is 720p. Other digital/HD
broadcast is 1080i. Only source of 1080p today is BluRay.

It's also the physical display. Now, most all displays today will take
both 720p and 1080i signal and convert them in real time to whatever
physical pixels you've bought. But the cheaper/smaller screens have
only 768 (!?!) vertical pixels (lines), while the larger/more
expensive ones have 1080 pixels (lines).

It is unclear what all this conversion does to the picture, there are
several other factors, but what it does is reduce the issue of how
many pixels to buy, to pretty much nothing but the screen size, and
the distance from which you will view it. Or even further, just the
screen size, since that is *already* typically determined by the
distance from which you view it.

So you can get away with the 768 screens under 40", in fact it may
even be better on smaller sizes, as smaller pixels would otherwise be
needed and less bright.


2. Some say you "can't tell the difference even if looking at 1080p
source" from 8-10 feet away if your set is under 46 or 50 inches.

Do you agree? Why would that be true? I would think, if it's lines
per inch that it wouldn't matter how big the set is.

The eyes are only so good.

Plus, all the compression/conversion artifacts tend to fuzz the issue
further.


3. this one only has 2 hdmi inputs. I guess one from satellite or
cable....and another one. Is that enough?

Usually, second from an upconverting DVD or a HD/BluRay. And/or a
gamebox, if that's not your HD/BluRay device. And/or a (new) PC.

So far I'm not using any.

J.

On Thu, 27 Dec 2007 06:57:49 -0800, kpb wrote:

1. What is the 720 vs 1080 thing anyway. Lines? Lines per linear
inch? Lines of "resolution"? It seems like there would be more than
720 lines on a TV screen. That's only about 20 per inch for a 40 inch
set. I know, stupid, stupid question. Believe it or not, they don't
really mention it.

A 40" set is roughly 26W x 20H. With a 720P set having a res of 1366x768,
that's 38.4 lines per inch, or 54 lines per inch with a 1080 set.

2. Some say you "can't tell the difference even if looking at 1080p
source" from 8-10 feet away if your set is under 46 or 50 inches.

Do you agree? Why would that be true? I would think, if it's lines per
inch that it wouldn't matter how big the set is.

Sounds about right from that distance.

3. this one only has 2 hdmi inputs. I guess one from satellite or
cable....and another one. Is that enough?

Would be for me. All I watch is recorded TV from a computers hooked to
mine. I use 1 HDMI port on one, and 1 VGA port on the other. With both sat
and cable, if you have both, you could use one HDMI and one component
inout, so 1 could be enough, or if it has 2 component inputs you wouldn't
need any HDMI ports. Depends on what *you* have to hook to it, and I don't
have that info.

--
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"kpb" wrote in message
...
I'm leaning toward a 42" plasma.

There is a lot to know about 720p vs. 1080p and I've read alot,
understood some.

I know that most don't broadcast in 1080p anyway.

Here's some questions.

1. What is the 720 vs 1080 thing anyway. Lines? Lines per linear
inch? Lines of "resolution"? It seems like there would be more than
720 lines on a TV screen. That's only about 20 per inch for a 40 inch
set. I know, stupid, stupid question. Believe it or not, they don't
really mention it.


720 and 1080 refer to the number of horizontal lines in the picture. That
is, the vertical resolution (NTSC is 480). CBS and NBC transmit 1080 lines,
ABC and FOX transmit 720. The 720 is paired with a horizontal resolution of
1280; 1080 is paired with 1920. TV sets don't necessarily use these numbers.
720P LCD sets tend to be 768 x 1366; so, the TV scales whatever comes in to
768 x 1366. Low end plasma sets below 50 inches will have a resolution of
1024 x 768. You will be able to see these pixels up to about 4 - 5 feet
away. BTW, on a good day the horizontal resolution of an analog NTSC picture
is about 330 lines. Digital SD is 640 x 480.

Tam






2. Some say you "can't tell the difference even if looking at 1080p
source" from 8-10 feet away if your set is under 46 or 50 inches.

Do you agree? Why would that be true? I would think, if it's lines
per inch that it wouldn't matter how big the set is.

3. this one only has 2 hdmi inputs. I guess one from satellite or
cable....and another one. Is that enough?

Sorry to ask simple probably redundant questions. Thanks for input
or opinions.

"Tam/WB2TT" wrote in message
. ..

"kpb" wrote in message
...
... BTW, on a good day the horizontal resolution of an
analog NTSC picture is about 330 lines. Digital SD is 640
x 480.

You can not compare directly 330 to 640. For analog NTSC,
330 is the horizontal resolution PER PICTURE HEIGHT. For
starters you need to multiply that number by 4/3. Once you
have done that you have the horizontal resolution expressed
in resolvable lines across the full screen width. 640 is
picture elements which has no simple relationship with
measurements of lines in the analog world. You need to
account for aliasing with any discrete type of sampling and
display. These analog/digital comparisons are made all of
the time without understanding exactly what is being
compared.

David

David wrote:

"Tam/WB2TT" wrote in message
. ..

"kpb" wrote in message
...
... BTW, on a good day the horizontal resolution of an analog NTSC
picture is about 330 lines. Digital SD is 640 x 480.

You can not compare directly 330 to 640. For analog NTSC, 330 is the
horizontal resolution PER PICTURE HEIGHT. For starters you need to
multiply that number by 4/3.

I think you mean 3/4.

And I don't know what that means as the technology is so different.
On the face of it the vertical resolution should be the number of scan
lines visible, which is roughly 500 interlaced. It's really in the
horizontal direction where digital has much higher resolution.

I have a different view of motion on the screen than what I see noted
here. Analog TV deals with motion in a low pass way, in effect softening
and blurring the hard edges.

jeff


Once you have done that you have the
horizontal resolution expressed in resolvable lines across the full
screen width. 640 is picture elements which has no simple relationship
with measurements of lines in the analog world. You need to account for
aliasing with any discrete type of sampling and display. These
analog/digital comparisons are made all of the time without
understanding exactly what is being compared.

David

"Jeff" wrote in message
...
David wrote:

"Tam/WB2TT" wrote in message
. ..

"kpb" wrote in message
...
... BTW, on a good day the horizontal resolution of an analog NTSC
picture is about 330 lines. Digital SD is 640 x 480.

You can not compare directly 330 to 640. For analog NTSC, 330 is the
horizontal resolution PER PICTURE HEIGHT. For starters you need to
multiply that number by 4/3.

I think you mean 3/4.

And I don't know what that means as the technology is so different. On
the face of it the vertical resolution should be the number of scan lines
visible, which is roughly 500 interlaced. It's really in the horizontal
direction where digital has much higher resolution.

I have a different view of motion on the screen than what I see noted
here. Analog TV deals with motion in a low pass way, in effect softening
and blurring the hard edges.

jeff


Once you have done that you have the
horizontal resolution expressed in resolvable lines across the full
screen width. 640 is picture elements which has no simple relationship
with measurements of lines in the analog world. You need to account for
aliasing with any discrete type of sampling and display. These
analog/digital comparisons are made all of the time without understanding
exactly what is being compared.

David

Then, for analog, there is the whole matter of contrast. TV manufacturers
will claim a horizontal resolution of 330 lines if you can see 165 fuzzy
dark gray lines and 165 fuzzy light gray lines. Basically, textooks define
it as 165 cycles of a sine wave at the output of the video amplifier. Also,
the 480 line vertical resolution can only be achieved if the video is
produced by a computer, or the vertical position of the camera is just
right.

Tam

Tam

"Jeff" wrote in message
...
David wrote:

"Tam/WB2TT" wrote in message
. ..

"kpb" wrote in message
...
... BTW, on a good day the horizontal resolution of an
analog NTSC picture is about 330 lines. Digital SD is
640 x 480.

You can not compare directly 330 to 640. For analog NTSC,
330 is the horizontal resolution PER PICTURE HEIGHT. For
starters you need to multiply that number by 4/3.

I think you mean 3/4.

Jeff,
I actually mean 4/3. The 330 refers to resolution of lines
counted on 3/4 of a scan line. Multiplying by 4/3 gives the
resolution for the entire line. Vertical resolution in
effectively the number of scan lines multiplied by the Kell
factor (.6 to .7) which accounts for the effects of aliasing
and cameras of that era. If video from a high resolution
source if processed by a computer before being sent, the
vertical resolution can approach the number of scan lines.
David

And I don't know what that means as the technology is so
different. On the face of it the vertical resolution
should be the number of scan lines visible, which is
roughly 500 interlaced. It's really in the horizontal
direction where digital has much higher resolution.

I have a different view of motion on the screen than
what I see noted here. Analog TV deals with motion in a
low pass way, in effect softening and blurring the hard
edges.

jeff