HD Resolution Question

[Operaghost]

I just purchased a Westinghouse TX-42F430S. I went to the local Comcast and swapped my DVR cable box for one that had an HDMI output. I got home, hooked it up, and started browsing around different channels to see if it was working properly. I noticed that on some the "HD specified" channels such as ESPNHD and the ABCHD, NBCHD channels that the resolution would shrink and not fill out the screen horizontally. However, the TNTHD and a few others would. So I was thinking that the channels that were shrinking the image were being displayed in 480 or maybe 720, however, when I checked the Info on the output, it read: HDMI: 1080i. So if it is in 1080i, why is the screen horizontally shrunk?

Also, are there any other comcast users that noticed that you have to change to the "HD specified" channel to view programs in HD, even though the normal version of the channel says "HD". Such as: Fox is Channel 5 for me, and on some programs will say "HD", but it still displays in 480 unless I change the channel to 705 which is FOXHD. Is that normal?

 

[FlashGordon]

I'll answer the last part first. Yes, to view HD material, you have to be watching the specified HD channel. The low number channel is primarily digital, not digital HD, for those who don't have an HD receiver or HD TV.
Not sure what you mean by shrinking resolution or filling horizontally, but the best HD channels in its fullest glory are ESPNHD and The Discovery channel. TNTHD, you have to be careful as some of their programming is upconverted. If its anything like its sister channel TBS HD, it definately ranks low in HD quality other than its sport programming.

 

[Kahnvex]

I don't know what the reason for that shrunken widescreen picture is, but I know that my NBC station here in town does the same exact thing, so it's not ouf of the ordinary, and it's not something you have control over either. You can zoom it in using the tv's controls, thats about it.

It also doesn't happen on every show.

Edit; OP, I'm referring to the OTA HD channels received on an antenna, if thats the same thing you're referencing. For some reason, a lot of the sitcoms and the news, etc on NBC come in as widescreen HD signals that dont' fill the whole screen. The rest of the OTA HD signals from other stations are correct, NBC is the only one doing it. Some weird local affiliate thing, as the Digital Cable has the same issue with that channel.

 

[ToastyX]

High definition and standard definition channels are separate, so yes, you have to be watching the HD channel to see content in high definition. HD channels generally stick to one format, such as 1080i, and standard definition content is generally upconverted to that format with black or gray bars on the sides to preserve the aspect ratio. TNT-HD is an exception. They display standard definition content stretched to fill the screen, which is annoying if you ask me since the image is distorted, and it can't be undone. Most cable boxes will let you stretch the image anyway, so I don't know why they do that. For SD channels, your HDTV is the one doing the stretching unless the cable box is set to do that. I don't recommend stretching the image since that distorts the aspect ratio. It should not fill the screen for SD channels.