# 1080i or 720p



## bobrap (Dec 17, 2005)

Just got my box this week and still playing with all the buttons. Just wondered which is the better setting to use, I'm going into a Samsung HLS4666W using component cables. Side note, just switched from D* and I'm really happy with the Vip622 so far.


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## LEADTECH DNSC (Jul 26, 2006)

bobrap said:


> Just got my box this week and still playing with all the buttons. Just wondered which is the better setting to use, I'm going into a Samsung HLS4666W using component cables. Side note, just switched from D* and I'm really happy with the Vip622 so far.


1080i is better


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## Mike Johnson (Jan 16, 2005)

The Samsung HLS4666W has a native resolution of 720p, so it would be best to set your new ViP-622 DVR for 720p as well. It won't hurt to try both 1080i and 720p on the 622 and see which one you like better.


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## wje (Mar 8, 2006)

It depends upon whether the scaler in your TV is better or worse than the scaler in the 622, plus a lot of other factors, such as the format of the original material. Unfortunately, the 622 doesn't have a native-passthru mode, nor does it have a quick way of switching between its scaling modes. So, you're basically screwed one way or another. Whichever you pick, it won't always be optimal.

In practice, it rarely makes a big difference. If you do a forum search, you'll see plenty of comments, flames, pedantic statements, and just plain confusion about the whole subject.

Try it out, pick what you like. Of course, you'll have to look at 8 different combos, and the best solution will only be best half the time anyway.

(source 720 vip 720 tv 720, 720 720 1080, 720 1080 720, etc)


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## ebaltz (Nov 23, 2004)

LEADTECH DNSC said:


> 1080i is better


Not. 1080i is actually 540p, so 720p is obviously better. But it does matter what the network broadcasts, what your TV is and what your box is set to. If all are 1080i, then go with that, but for almost everything else stick with 720p. Of course you could also get a 1080p set and wait for who knows when anything will actually be broadcast in that format.


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## LtMunst (Aug 24, 2005)

wje said:


> It depends upon whether the scaler in your TV is better or worse than the scaler in the 622,....


Exactly. On my Panasonic (720p native) 1080i material looks much better if I set the receiver to output 1080i rather than 720p. Definately a better scaler in my TV. Signals that are 480 or 720 do not look any worse with the receiver set to 1080i....so that's where I keep it for everything.


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## redbird (May 9, 2005)

ebaltz said:


> Not. 1080i is actually 540p, so 720p is obviously better. But it does matter what the network broadcasts, what your TV is and what your box is set to. If all are 1080i, then go with that, but for almost everything else stick with 720p. Of course you could also get a 1080p set and wait for who knows when anything will actually be broadcast in that format.


1080i is NOT 540p as far as resolution goes. 540p only has 540 scan lines but 1080i has twice that, it just takes two scans to make each frame instead of one so motion will look a little blurry compared to p.


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## James Long (Apr 17, 2003)

ebaltz said:


> 1080i is actually 540p,


No, it is not. There are more pixels per line on 1080i and alternating fields are sent at (usually) 30 full frames per second. 540p sends a full frame (every pixel you are going to get) 60 frames per second (usually). Counting alternating fields as if they were full frames is not accurate and does not take into account the full width of the lines.

_(Note that compression affects all DT formats. Nobody is getting 30 or 60 'full frames' per second OTA or via satellite -- they are getting key frames and changes. That affects all digitized TV which is why it is not mentioned above.)_


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## ebaltz (Nov 23, 2004)

James Long said:


> No, it is not. There are more pixels per line on 1080i and alternating fields are sent at (usually) 30 full frames per second. 540p sends a full frame (every pixel you are going to get) 60 frames per second (usually). Counting alternating fields as if they were full frames is not accurate and does not take into account the full width of the lines.
> 
> _(Note that compression affects all DT formats. Nobody is getting 30 or 60 'full frames' per second OTA or via satellite -- they are getting key frames and changes. That affects all digitized TV which is why it is not mentioned above.)_


Read up on it: http://alvyray.com/DigitalTV/Naming_Proposal.htm


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## n0qcu (Mar 23, 2002)

ebaltz said:


> Read up on it: http://alvyray.com/DigitalTV/Naming_Proposal.htm


That page is just anothers persons OPINION not fact.


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## liferules (Aug 14, 2005)

I ditto what everyone else says, check both 720 and 1080 on your set and pick whichever looks best to you. I would also suggest testing them on sports channels to see if you get jaggies with fast motion in one...

I tire of the 540p vs. 1080i argument. Neither group will be convinced otherwise, so lets just drop it.


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## Ron Barry (Dec 10, 2002)

Not really a 622 specific support issue so felt it was better to move it over into the HD area.


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## James Long (Apr 17, 2003)

Regarless of that proposal, 540p will NEVER equal 1080i. There are still more horizontal dots in a full frame image. The ATSC did quite well accuately naming their formats. The fact that we ignore the frame rates and widths when mentioning the format name does not change the fact that 540p and 1080i are different beasts.

That being said, I prefer 720p as a broadcast standard because it gives a comprable image with less pixels (needing less compression to fit in the same space) yet more refreshes of those pixels for fast action. It doesn't change the fact that many networks are transmitting in 1080i/30, that my set is native 1080i/30 and setting my 622 to 1080i/30 means one less conversion (the set doesn't have to convert 720p to 1080i to display it).


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## bobrap (Dec 17, 2005)

Thanks Ron, didn't know for sure which to post in, and didn't mean to start such a hot discussion. Just trying to figure out all this new hi-tech stuff and want to get it right. Thanks everyone.


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## Stewart Vernon (Jan 7, 2005)

I promised myself last time that I would not jump into the 1080i vs 540p vs 720p vs hand-drawn sketches on a napkin debates... My brain still hurts from the last time!


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## Taha24 (Jun 15, 2006)

Yea im not getting into that either.

I have mine set to 1080i since my TV is capable of 1080p. So I let the the TV descale the interlaced signal into a 1080p signal.


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## sNEIRBO (Jul 23, 2006)

James Long said:


> Regarless of that proposal, 540p will NEVER equal 1080i. There are still more horizontal dots in a full frame image. The ATSC did quite well accuately naming their formats. The fact that we ignore the frame rates and widths when mentioning the format name does not change the fact that 540p and 1080i are different beasts.
> 
> That being said, I prefer 720p as a broadcast standard because it gives a comprable image with less pixels (needing less compression to fit in the same space) yet more refreshes of those pixels for fast action. It doesn't change the fact that many networks are transmitting in 1080i/30, that my set is native 1080i/30 and setting my 622 to 1080i/30 means one less conversion (the set doesn't have to convert 720p to 1080i to display it).


That is what I've always been told too - set all your outputs / inputs to the native resolution of your set and there's a lot less processing time involved. Don't make the TV work harder to upconvert / downconvert to match it's resolution.

As far as 1080i v 720p goes, my thoughts on the subject have always been that I'll take a 150% increase in resolution with a 50% reduction in frame rate. My eyes can detect improved resolution, but my brain can't detect the difference between 30fps and 60fps - both are too freaking fast for me to comprehend. And usually when I point out to people that the movies they watch in a theatre, and they think are so fluid and smooth, are only 24fps they tend to agree that the improved resolution is the way to go.


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## James Long (Apr 17, 2003)

I'd love to see films broadcast in 24fps. What a natural way to save bandwidth and remove one more conversion step (converting from 24 to 30 frames). So far, nobody is taking up my request.


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## P Smith (Jul 25, 2002)

ebaltz said:


> Not. 1080i is actually 540p, so 720p is obviously better. But it does matter what the network broadcasts, what your TV is and what your box is set to. If all are 1080i, then go with that, but for almost everything else stick with 720p. Of course you could also get a 1080p set and wait for who knows when anything will actually be broadcast in that format.


If first part is obvious, just count lines on any 1080i TV screen under magnifying glass , but second was obsolete before typing  - grab Toshiba HD DVD player and HDDVD disk and you'll see 1080p output RIGHT NOW!


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## wje (Mar 8, 2006)

James Long said:


> I'd love to see films broadcast in 24fps. What a natural way to save bandwidth and remove one more conversion step (converting from 24 to 30 frames). So far, nobody is taking up my request.


There's actually a problem with 24fps for video (other than the display rate mismatch)... for film, the entire frame is presented at once, there's no scanning. When 24fps is displayed on a video monitor when the image is drawn by scanning (such as CRT's), many people can see flicker.

Even at 30fps, flicker can be noticed by some people. It's not a problem for TV in general. NTSC 480i is actually drawing 60 images/sec, even lines in one pass, then odd lines, giving a full refresh of 30fps, but a 'half' field refresh at 60fps. 720P does 60 full frames/sec, 1080i is like the old 480i, 60 half-frames/sec. Of course, with some of the new display technologies, the image is essentially presented all at once, like film

If you've ever seen European PAL or SECAM tvs, you can probably see flicker. I can't watch PAL it's so bad. PAL uses a slower refresh rate than NTSC, 25fps (625 lines, interlaced, with 50 half-frames/sec).

Incidentally, the 60 fps rate for 720p is why it does better at showing quickly-moving images, like sports. With interlacing, one half-frame is actually happening 1/60th second later, so quickly-moving objects get alternating-line 'jaggies'. A large part of deinterlacing processing involves trying to realign the half-frames to avoid them.


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## ebaltz (Nov 23, 2004)

P Smith said:


> If first part is obvious, just count lines on any 1080i TV screen under magnifying glass , but second was obsolete before typing  - grab Toshiba HD DVD player and HDDVD disk and you'll see 1080p output RIGHT NOW!


HD-DVD yes, I said "Broadcast". Wait is that a pig in the sky I see? And it has wings?


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## P Smith (Jul 25, 2002)

Dish made one time a sound about bringing 1080p soon.


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## Jim5506 (Jun 7, 2004)

sNEIRBO said:


> As far as 1080i v 720p goes, my thoughts on the subject have always been that I'll take a 150% increase in resolution with a 50% reduction in frame rate.


Actually the pixel rate for 1080i/30 is only 12% larger that the pixel rate for 720p/60.


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## Mike D-CO5 (Mar 12, 2003)

P Smith said:


> Dish made one time a sound about bringing 1080p soon.


 Oh yes and you will have to upgrade to another new 1080p receiver. I'll wait on this one. I won't be spending anymore more money for quite a while on hd. I am all tapped out.


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## tnsprin (Mar 16, 2003)

wje said:


> There's actually a problem with 24fps for video (other than the display rate mismatch)... for film, the entire frame is presented at once, there's no scanning. When 24fps is displayed on a video monitor when the image is drawn by scanning (such as CRT's), many people can see flicker.
> 
> Even at 30fps, flicker can be noticed by some people. It's not a problem for TV in general. NTSC 480i is actually drawing 60 images/sec, even lines in one pass, then odd lines, giving a full refresh of 30fps, but a 'half' field refresh at 60fps. 720P does 60 full frames/sec, 1080i is like the old 480i, 60 half-frames/sec. Of course, with some of the new display technologies, the image is essentially presented all at once, like film
> 
> ...


Still should be broadcast that way i.e 24 fps. Then would be the job of the tV or receiver to decide on the best way to display it so that flicker is not noticable.


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## wje (Mar 8, 2006)

Actually, 1080p/24 is a supported ATSC format. Also, many DVDs are encoded at 24fps. The player then does the 2:3 pulldown itself. So, theoretically, you could see movies at 24fps. (The 24fps encoding is why progressive-scan DVD players look so much better. Rather than doing field pulldown, they can do frame pulldown. Fewer artifacts.)

Practially speaking, though, very few people think the difference between native and pulldown is significant enough to warrant the effort.


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