My apologizes if this topic has been covered on AVS. I searched for a thread and didn't find this information.

There's much discussion about the quality of HD broadcasts, I need some clarification.

It's my understanding that even when watching an HD channel, unless the content used the HD standard through post production and rendering, we may not be watching true HD content.

Furthermore, movies broadcast in HD stations aren't necessarily true HD unless they are transferred from film using the HD spec (1080P or 720P).
Is this correct?

It's obvious that Letterman and Leno look remarkably better than say, a 1990 movie on TNT-HD although both are broadcast at 1080HD. I assume these last night talk shows are examples of true HD. They look spectacular.

Thanks,
Rabdaddy

Deja Vu? I could have sworn I just answered this question.

There are three sources of high-definition content: Sports, news, award shows, concerts, and other video content acquired in native 1080i60 or 720p60 with HD cameras.


Movies and series content acquired in 1080p24 with HD cameras.


Movies and series content telecined from actual film stock to 1080p24. Quality of the high-definition picture will vary depending on the quality of the film print used for the digital transfer.

TNT-HD is not a good example to use. TNT-HD is not a 100% HD channel, like say HDnet or Discovery. Much of TNT-HD's programming is in high-definition (telecined from film), but they still have a lot of 4:3 480i content, which they stretch (distort) to fill the screen. This stretched 4:3 content is not high-definition; it is upconverted SD.

The broadcast networks (ABC, CBS, FOX, NBC) offer most of their primetime (8-11pm) lineups in high-definition, plus some mid-day soaps and late night (Leno, Letterman, etc), as well as sporting events, but most of the remaining content is upconverted SD. If a program is broadcast in 4:3 with side bars, it isn't in high-definition (99.9% of the time).

With exception to pre-1960 movies, all high-definition programming is widescreen; if it's not widescreen, it's not HD. Note that not all widescreen programming is in high-definition. I mentioned the example of TNT-HD above, which stretches 4:3 SD content to fill widescreen displays. Showtime also has some 480i/480p widescreen content that they upconvert to high-definition --- this content is true widescreen, but it's a DVD-quality source, not sourced from a 1080p24 master. Showtime does differentiate between the two in its online schedule at Sho.com.

Yeah, I saw this thread after posting. Sorry for the cross post.
Again, thanks for the extended info. You know your stuff.

The "4:3 is not HD" mantra isn't right once those TV shows get out there remastered in HD. (I Love Lucy, Frasier, Buffy, Angel, X Files, Seinfeld, Friends, etc)