1080i vs 480p

pillarRock217

Here's a question for those of you who have seen an actual HD display. I bought my HDTV a few weeks ago and still have yet to see a true HD signal, because Comcast doesn't offer it in my area. How does 1080i look vs 480p? More so, how does a smaller progressive resolution compare in quality to a bigger resolution that isn't progressive?

TeeJay1952

HDTV when all the ducks are in a row is amazing.
My wife thought I was crazy to spend 2k on XBR960 but went along for the ride. She loves it. Soundstage on PBS and Football on ABC have sold her. Prime Time is usually in HD and when show is filmed in HD, Broadcast in HD and recieved in HD (those ducks in a row I mentioned earlier) it is an unsurpassed video delight.

TheFramer

Which HD TV did you decide on ?
I am planning to replace my TV with a Plasma HDTV - just thought I'd see what you went with.
Thanks

rbinck

The progressive vs. interlaced arguments had its roots in the computer world. The progressive scan for a computer monitor is a must as interlaced promotes flicker and if the persistance of the phosphers was long enough to try and eliminate the flicker then there would be trails left behind on fast moving objects. Most computer monitors operate at much faster frame rates with faster phosphers.

What the early pioneers wanted for a HDTV standard was 720p and they used the computer argument as the basis for their position. What was left out in the argument was the resolution between the two formats. They based the 720p being better than the 1080i on data that applied to CRT based computer monitors.

First it is necessary to know what type of display is being talked about as the issues are completely different between flat panel, fixed pixel displays and CRT based displays, such as the XBR960.

Fixed pixel displays are by nature progressive because they have discrete light source or reflectors for every pixel. You can think of the display as a large memory plane that may be scanned for the ultimate display output, but it does not necessarily have to be scanned at the rate which the signal is received. It is possible for a plasma display to be updated many times more out of the screen memory than is the rate the individual pixels are updated into the screen memory. This is also true of video that is displayed on a computer monitor, even with the analog VGA type output. For example right now my computer monitor is running at 75hz. This means the entire screen is scanned 75 times a second. If I view a TV picture out of my TV tuner card, it will update the screen memory at the rate of 30hz, or 30 new complete frames each second, but the screen video is still being updated at 75 times a second. This is important to understand as it relates to flicker in fixed pixel displays.

Now to CRT based displays. They are analog in nature in that a CRT based display does not have a memory plane that the display scan is retreived from, so progressive vs interlaces becomes more of an issue. Most TV displays are designed about the 30 frames per second here in the USA and the persistance of the phosphers (the amount of time the phospher stays lit) is such as to accomodate 30 frames per second. That is one of the reasons why HDTVs do not make very good computer monitors. When people speak about the progressive scan updating the screen twice for every full interlaced scan, they eliminate the fact that if the phospher from the first scan is still lit, the faster screen update rate didn't help. And this would be the case for any CRT that would be capable of displaying an interlaced picture. CRT based HDTV therefore these days generally will settle on 1080i as the display rate no matter what the input signal that is received. The input signal is converted to 1080i for display even when a 480p signal is received.

So what the PQ will boil down to is the number of pixels that the two formats contain. 1920x1080 equals 2,073,600 and 720x480 equals 345,600 so which would expect to have more detail? The 2 mega pixel of course. Now the difference between 1080i and 720p is much closer and most people can not tell the difference in those two formats, although when I display digital photographs in the two formats the 1080i will win out because the static photo does not introduce any interlace artifacts. I do notice a greater degree of flicker on computer text at 1080i, however.

To sum up this post, I would say that you will notice a great deal of difference between 480p from a DVD and 720p or 1080i HDTV broadcasts, particurarly on the distance shots.

pillarRock217

In reply to TheFramer, I got an RCA 52" (D52W20). It didn't look as good as most of the other models I saw, but I bought it for the cost factor. I'm still in high school and work at a grocery store, so I was on an extremely tight budget. Fortunately, since it's going in my family room, my Dad is splitting the cost with me. A quick review of the product: 480i cable looks terrible, waiting for HD to arrive in our area, 480i DVD looks pretty good, considering the signal. So I have a lot of room to upgrade, next month I'm going to get the Denon 1910 to upgrade from my Bose 321 media center, and I'm also going to upgrade to monster cables. Anyhow, the TV was a vast improvement over our previous one, and we got it for $1,499. Definitely worth it if you are on a tight budget.

maximus

As good as reference 480p dvd can look, true 1080i pretty much embarasses it.
Just my 2 cents as rbinck completely answered both your questions.


Here is a link which explains differences between spatial and temporal resolution;
http://www.hd3dmovies.com/tech.html

goatholes

I also bought that 52" RCA because of the cost factore - Best Buy had it on the day after thanksgiving for $999 - $50 if you had a points card. I just now purchased the LG HDTV OTA reciever, and the picture is great, when the program is actually broadcast in HD. What I am finding is that much of the programming I have found so far looks like normal 480 (which the receiver upcodes to 1080 and it doesnt look so great). My daughter loves the PBS cartoon channel in HD however..... When a channel is in HD, you can definately tell the difference...

Micmax

A word on Monster Cables...the concensus thus far on this forum suggests that Monster Cables really don't noticably show an improvement. They're good-looking cables with a lifetime warranty, and they carry some prestige to fellow Home Theatre enthusiasts. I've purchased a number of Monster Cables (Component3, Optical, Woofer) and also a bunch of cheap cables from Wal-Mart. I've yet to see/hear a difference in anything.

It sounds like you are on a tight budget (like me, only in college). You may be straining your wallet more than its worth with Monster Cables.

fritolayguy

Mediacom in Springfield, MO. started offering HD channels about three months ago, and I had them hook up a DVR with HD to my Sony 61"HDTV about a month ago. We have multiple TV's, two TIVO units, and varying levels of picture quality, but I can honestly say that when I turn to an HD channel on my Sony big screen , and the display reads 1081i format, the picture is STUNNING. That's the only way I can translate the depth and breadth of the experience we get from HDTV in the 1081i format.

__________________
Enjoying my Sony 61" HDTV
1081i signal from Mediacom!

drecar

I recently purchased the Samsung HCP4741W and Star Choice DSR500 to replace my 32'' Sony Vega and 400 series sat receiver. Over all I am happy with the performance for the buck, however I disagree that 1080i looks better than 480p. Could there be a malfunction since various statements above are fairly strong or is it the limitations of the display? Time and time again I have played with the settings on the DSR500 and for PQ 480p looks better on HD and SD programming. 1080i seems softer and slightly dimmer. 480p offers a smoother picture, more DVD like picture. Watching DVD's is still more impressive however with certain programming the results are approaching my DVD experience. I am tempted to tweak the settings again if I can obtain a petter picture. Any comments?

maximus

I'm not sure what but something is amiss in your setup, a good HD signal is unmistakable.

borromini

480p looks better than 1080i with an HD signal!?! It's got to be equipment and/or settings that's giving you that impression. When properly set, a 1080i HD image blows away 480p...not even close. I've heard arguments between 720p or 1080i...both HD resolutions but never 480p. Now 480p looking better with SD signals is a real possibility. Double check everything. If you saw the 1080i HD image on my display and compared it to 480p of the same HD signal you would agree that it has to be equipment/settings or even the signal itself.

__________________
"I'd rather have a bottle in front of me than a frontal lobotomy"

TeeJay1952

How is tv getting signal? Are you connecting with Svideo or composite or component cables?

drecar

Thanks for your responses fellas. The video signal is connected directly to the TV via component inputs with good quality cables. As I write this, I am wondering if it is possible that only one of the two component inputs on my tv is compatible with 1080i? I'll check that tonight. The way you guys a talking, one would have to have seriously impaired vision not to see that 1080i is clearly superior.

rbinck

That is correct. It is possible that one of your component video connections is specially set up for a DVD player and is causing the abnormality. I have seen such TVs in the past. Toshiba color stream inputs come to mind. Let us know how it turns out.