720p vs. 1080i

[ascendedcobra]

For me everytime I watch LOST on abc hd (720p) It looks decent. If I download the same episode off the PSN store via PS3 or Zune via Xbox 360 at 1080p then the picture is excellent. The PQ will be much better and almost bluray quality.

[volcomsocal]

Originally Posted by dobyblue

Care to explain?

720 lines always on the screen looks smoother than 540 lines, then 540 lines again. IMO progressive is better than interlaced.

[nycomet]

Originally Posted by volcomsocal

720 lines always on the screen looks smoother than 540 lines, then 540 lines again. IMO progressive is better than interlaced.

Is that with both eyes being used at the same time? I believe your comparison is subjective, depending on one's vision. Use of eyeglasses or contact lenses can also change the way one perceives image quality (and how many cocktails one consumes as well).

[ScuseMe]

Originally Posted by nycomet

Is that with both eyes being used at the same time? I believe your comparison is subjective, depending on one's vision. Use of eyeglasses or contact lenses can also change the way one perceives image quality (and how many cocktails one consumes as well).

There's a nice technical explanation of this debate here - Is 720p better than 1080i?.

[lobosrul]

Originally Posted by ScuseMe

There's a nice technical explanation of this debate here - Is 720p better than 1080i?.

Theres at least one serious mistake in that article. Shows like SNL, and David Letterman are not shot at 24p. They're pure interlaced when broadcast, there is no 3:2 cadence. So they're either shot with 1080p cameras at 60 fps and then interlaced, or shot at 1080i.

[dobyblue]

Originally Posted by volcomsocal

720 lines always on the screen looks smoother than 540 lines, then 540 lines again. IMO progressive is better than interlaced.

But that is only how a 1080i signal is displayed on a CRT, and I don't think too many people here are watching CRT's.

On any plasma or LCD the original 1920x1080 progressive frame (24Hz or 30Hz) is reconstructed. 1080p24 converts to 1080i60 and back to 1080p24 again.

So for movies a 1080i60 signal of a 1080p24 source would surely be better than 720p. The only time I can see 720p being better would be for extremely fast sports where the filmed frame rate is higher, however I am also aware that shooting at 1080i60 and using bob deinterlacing wouldn't lose temporal resolution.

Originally Posted by lobosrul

Theres at least one serious mistake in that article. Shows like SNL, and David Letterman are not shot at 24p. They're pure interlaced when broadcast, there is no 3:2 cadence. So they're either shot with 1080p cameras at 60 fps and then interlaced, or shot at 1080i.

They would likely be shot at 1080p30, not 1080p60, then interlaced to 1080i60 as that's what CBS broadcasts in. I wouldn't think they'd actually film in 1080i.

Originally Posted by ascendedcobra

For me everytime I watch LOST on abc hd (720p) It looks decent. If I download the same episode off the PSN store via PS3 or Zune via Xbox 360 at 1080p then the picture is excellent. The PQ will be much better and almost bluray quality.

LOST is archived at 1080p24. They lose 1/2 the resolution on their broadcast. I wouldn't think ABC would give the 1080p master to PSN and 360 though, they probably upconvert it. Are you watching direct OTA from an ABC station or through a cable/satellite provider? If the latter that might explain the loss of quality.

[slick1ru2]

Originally Posted by wilky61

If you're viewing something with a lot of fast motion (e.g., sports or action films), you'd probably get more benefit out of 720p.

And that is the reason Fox was saying it is the best of the two. If you watch a baseball game the ball is an oblong blob when thrown. If you watch the same game in 720p, especially OTA where it is not compressed, it looks more like a spinning ball.

[PaulGo]

http://www.youtube.com/watch?v=Z-JXfyvlPh0

[slick1ru2]

Originally Posted by PaulGo

http://www.youtube.com/watch?v=Z-JXfyvlPh0

Which showed the blurred ball in 1080i which is why its better to watch sports in 720p.

[PaulGo]

With today's technology progressive scan will result in a better picture for scenes which are moderate to fast moving.

[DIGITALBATH]

Really? Like soccer/futbol? I watched the world cup on my 54 inch Pansonic Plasma. ABC=720p and CBUT-1080i. From where I sit-6.83, 1080i looks much better.

[Dreemworx]

1080p (Blu Ray) best then 1080i (HD TV) then 720p.

I really do not care for 720p on my 52" Sony.

Watch Planet Earth on HDTV in 1080i and it is remarkable.

[PaulGo]

Beauty (or HD Quality) is in the eyes of the beholder. I have a 67" Samsung DLP (1080p display) and 720p looks great. Also when stations but multiple channels on e.g 4.1,4.1,4.3 the 1080i signal becomes bit starved a lot faster than 720p.

Bottom line - both 720p and 1080i can look great but for fast motion 720p does a better job.

[radagast]

Originally Posted by McGarnigal

With 720progressive you are getting 720 lines of resolution continuously. With 1080interlaced, you are seeing 540 lines of resolution, two sets of 540 lines are taking turns appearing on your screen, but at a rate too fast for the human eye to discern the switch. 720 lines > 540 lines. A lot of tv channels are 1080i, as well as crt hd tvs are capable of native 1080i, but not 720p. Hd video (not film) looks very nice in 1080i as well.

The problem is you need to take the how the eyes and brain see and interpret data. Continuously at what speed? And by the time the human brain has processed visual data, how many lines of resolution are perceived?

[RBBrittain]

Originally Posted by mugen302005

Hi folks...

I certainly have no idea where to post this maybe stupid question. Is directv offering FULL HD broadcasting? I came across a site where people are simply kicking people's ass when someone tells them there is no such thing as 1080p over cable tv stations. Or isthere?

Sorry to bump in.

IIRC, DirecTV (and Dish) only offer 1080p on VOD movies. All HD broadcasting (OTA or cable) is either 1080i or 720p.

[RBBrittain]

Originally Posted by radagast

The problem is you need to take the how the eyes and brain see and interpret data. Continuously at what speed? And by the time the human brain has processed visual data, how many lines of resolution are perceived?

There's a lot of factors to consider. For one, interlaced scan really does its magic only on CRTs; other screens must convert it to progressive scan to avoid herringbone effects on vertical edges. OTOH, 1080i normally has more horizontal pixels per scan line (though not in "HD lite"); and for a properly-designed video processor, high-quality 1080i > 1080p upconversion should be fairly easy.

(Edit: Personally, I think the ATSC made the right choice by declaring them equal back at the dawn of HDTV; which one is better is a matter of personal preference and/or conversion strategies.)

[Canada]

1080i has a greater resolution than 720p but 720p is all lines are present all the time. A side not about my Toshiba 34" CRT TV for some reason can not do 1080i on Blu ray properly, there are big black lines running through the image. When I'm watching 1080i TV however the image is absolutely fine, go figure.

[Buddy Christ]

Size ad distance.


720 good 32 inch screen 6 feet away.
720 bad 42 inch 6 feet away.


1080 good 42 inch and up 7 feet away and further.

Meaning a 32 inch or less at 1080 is pointless.

[BillieCassin]

Originally Posted by Blu2U

Meaning a 32 inch or less at 1080 is pointless.

Intellectually, I know it's true - but I paid the extra twenty bucks (yup, $20) to get the 1080p version of the TV I wanted versus the 720p, even though it's only 32". Psychologically I need to see that "1080p" come up when I run a Blu-ray, or I wouldn't feel like I was watching real HD. Crazy, but true.

[NYorker]

When I first got my plasma I set the input to 1080i, then compared to to 720p. Switching to the latter made the PQ a whole lot smoother! made me wonder what's the great benefit in 1080i.