Originally Posted by CAVX
So in the US, are the SD channels 4 x 3?
I can't remember seeing SD in full 16:9 - it's always 4:3, as far as I can tell, but I'm new to digital TV and 16:9 displays.
What's more, there are 16:9 programs syndicated and rebroadcast in SD, so while the geometry and full frame are preserved, they are not only low resolution, but also window-boxed. Thankfully, the zoom function on my TV takes care of some of that... For instance, there's a late-night talk program (Tavis Smiley) that my local public television channel broadcasts in HD. The next day it's rebroadcast to fill a daytime slot, but window-boxed. That's mostly an exception, however. There's a local network syndicating "Bones" and several "CSI" programs, which are all (or at least mostly) originally 16:9 and HD. The rebroadcast in syndication is usually cropped 4:3 (not sure of the resolution, to be honest).
I'm not sure what those smaller stations are doing with their bandwidth - some of them may be multi-casting several other SD channels as well - mostly infomercials. Seems like nonsense, but for now at least, that's the way it is.
The local news programs got all excited when they went HD in the studios (prior to the DTV transition), but the cameras they take on location are still generally SD. So, they put up some logo or other screen fillers to take the place of pillars, but it's painfully obvious they're SD.