Hi folks, I've got another noob question for you.

How do I tell the difference between 720p and 1080i when watching HD programming? The only show I've seen in HD so far is Heroes, and I see some weird blurring sometimes, so I'm guessing it's 1080i.

The only way I can tell when a show is HD is when the black bars on the sides disappear. Does this happen for both 720p and 1080i? Or would 720p still keep the black bars but have a sharper picture?

I've recently started using my first widescreen HDTV, and am getting used to seeing black bars on the sides of the screen. However, in some shows I'll also see black bars on the top and bottom as well.

Can someone tell me why there's so much black? :( It's like I've lost 1/3 of my screen real estate.

Hi folks, I've got another noob question for you.

How do I tell the difference between 720p and 1080i when watching HD programming? The only show I've seen in HD so far is Heroes, and I see some weird blurring sometimes, so I'm guessing it's 1080i.

The only way I can tell when a show is HD is when the black bars on the sides disappear. Does this happen for both 720p and 1080i? Or would 720p still keep the black bars but have a sharper picture?

I've recently started using my first widescreen HDTV, and am getting used to seeing black bars on the sides of the screen. However, in some shows I'll also see black bars on the top and bottom as well.

Can someone tell me why there's so much black? :( It's like I've lost 1/3 of my screen real estate.

Whether or not you can even distinguish between 720p and 1080i depends on the native resolution of the tv itself. If your tv's native resolution is 720p, then 720p is all you will see, even if the broadcast is in 1080i. If your tv has the ability to display 1080i content, then you may see a difference between the two (if you have good eyes).

I have a tv with 1080p resolution and everything looks great...but I notice a slightly sharper picture on channels like Discovery HD Theater, and Universal HD (which both broadcast in 1080i).

As far as those black bars on the screen are concerned, many theatrical movies are filmed at a wider aspect ratio than the 16:9 on our wide screen tvs, therefore, you're going to see those black borders regardless of the size and shape of your screen. Some tvs may allow you to zoom in to eliminate the borders however, you may lose some of the picture on the sides (which defeats the purpose of HDTV).

Black bars on the sides of the screen appear when a non HDTV program is showing on an HDTV channel. You may or may not be able to expand the picture, (to make it look like widescreen) however, I think you're better off just watching it the way it is.

DVDs (standard) may have black borders also. You should be able to zoom on those to minimize or eliminate the borders. My tv shows borders on DVDs
and a stretched picture until I zoom in on the picture. This corrects the stretched picture and maintains the correct aspect ratio and (in some cases) fills the entire screen.

I hope I haven't confused you with the above info. If you're new to all this new technology, you may want to experiment with the picture size and read the owners manual on your tv which may help you through some of the confusion.

I really can't tell a difference between the two. At the beginning of the year, I went through four different HDTV's before I finally found one with good PQ. I went from a 720p LCD, to a 1080p LCD, and finally to a 720p Plasma. More specifically, an LG 42" Plasma. I was blown away by the PQ. Don't let the 720p/1080i standards confuse you... it really just depends on the source...

For example, to me, CBS 1080i looks a lot better than NBC's 1080i...much more detail and color. ABC's 720p looks better than FOX's 720p... And, for me anyway, ABC's 720p looks better than NBC's 1080i. It really depends on your eyes.

I own a Sanyo 26" LCD HDTV. It comes as 720p out of the box and downconverts 1080i. When an HD television show has non-HD segments or (most) commercials, the picture is being pillarboxed, which is a similar idea to letterboxing, only it's flanking the picture, rather than being at the top and bottom. The only time it irritates me is if I'm watching an older widescreen movie in a 4:3 aspect ratio. Yes, I can zoom in, but I DO NOT want everything stretched and I don't want to lose any more picture quality. :(

There are two basic ways to tell the difference between 720p and 1080i:

1. Your equipment (set-top box or tuner in the TV) tells you.

2. You note what channel you're watching, and derive it from that. ABC, FOX, and their associated channels (ESPN, NGC) are 720p. Pretty much everything else is 1080i.

The "by looking" method is not reliable for distinguishing 720p from 1080i. However, if the only way you can tell HD from SD is by the black bars, you may have a problem.

Both HD resolutions are 16:9. You get the sidebars mainly on "upconverted" material; i.e., stuff that originated as SD. You get the "postage stamp" effect -- bars all around -- on letterboxed SD upconverts. You may or may not be able to compensate for it via a zoom mode in your set.

Most of the time it is difficult so see any difference.

I can tell 1080i from 720p on my 720p TV by the occasional interlace artifacts.

Also note that not everything with black bars will be SD. For example, Star Trek: The Original Series was shot on film in 4:3 format, and so the new HD transfer is also 4:3 with the side bars.

I can tell 1080i from 720p on my 720p TV by the occasional interlace artifacts.Since most content on 1080i channels is actually a 1080p24 source, the fact that you see interlace artifacts suggests that your display does not correctly handle those signals with inverse telecine. On a display that correctly handles 1080i signals with inverse telecine, you will not see any interlace artifacts on movies or series programming.

More information in this thread (http://www.avsforum.com/avs-vb/showthread.php?p=9896981&&#post9896981).

In its latest issue, Home Theater Magazine reviewed and compared (http://www.hometheatermag.com/rearprojectiontvs/207rptvface/) the top 60" 1080p RPTVs from JVC, Mitsubishi, Olevia, Samsung, Sony, and Toshiba. Only two of the six could correctly detect and display 1080p24 content delivered in a 1080i60 transmission, such as Heroes on NBC and CSI on CBS. The other four displays could not -- they weren't able to display the original 1080p source, with full 1080p resolution and no interlace artifacts, on those programs.

Actually, the telecine thing appears to be more complex than you'd expect. If you record a show like _Heroes_ or _Las Vegas_ (using MythTV), and go through it frame by frame, you find the telecine pattern _most_ of the time. However, at certain times, such as the trademark _Las Vegas_ "fly through the casino" shots, the telecine patten is broken. That's when I sometimes see an interlace artifact, whether watching the show live or on the MythTV box. (not always, though, my TV seems to do a decent job even then)

My guess is they do some of the digital editing after the telecine.

Actually, the telecine thing appears to be more complex than you'd expect. If you record a show like _Heroes_ or _Las Vegas_ (using MythTV), and go through it frame by frame, you find the telecine pattern _most_ of the time. However, at certain times, such as the trademark _Las Vegas_ "fly through the casino" shots, the telecine patten is broken. That's when I sometimes see an interlace artifact, whether watching the show live or on the MythTV box. (not always, though, my TV seems to do a decent job even then)

My guess is they do some of the digital editing after the telecine.The display's processing has to be able to switch between video and film modes on the fly, based on what it detects as the source content (60i or 24p). Not all video processors and displays are able to do this well. Some display processors can detect and switch between video and film mode relatively fast (within a few seconds), whereas others may take 30-60 seconds.

I'm hoping someone will come up with a better test for this high-definition IVTC in displays. As you say, sending a constant 1080p24 stream in 1080i format is a little different from what we have in the real world with broadcast and cable. On broadcast and cable, we have frequent commercial breaks, as well as occasional edits, where the source content (cadence) switches between video and film. I think a better test would measure the "speed' and reliability at which a display can switch between video deinterlace and film (IVTC) modes.

If you think about it, standard definition (SD) is the same way, and a number of video processors have gotten pretty good at switching between film and video modes on the fly [for SD]. Yet, even after all this time, some cheaper processors still have trouble with that.