I was trying to figure out the logic behind why some channels allow you to change aspect ratios and why some do not. Also, some channels do not allow me to make use of the gray side bars on my Panasonic Plasma to reduce the chance of burn in if I watch a program in 4:3 ratio. Incidentally, the same channels that don't allow me to change the aspect ratio are the same ones that don't allow me to change the gray side bars. I'm stuck with black. Any insight would be appreciated.
Yes, now that you mention it, it does seem only to apply to the local HD channels. Some of the programs that are broadcast are in wide screen, but the local news and the like are in 4:3 format and cannot be changed.
I could be wrong, but some models of TV won't let you change the aspect ratio while watching a 1080i widescreen format. Although the local stations are broadcasting a SD picture, the black bars are embedded into the picture making the TV believe it is seeing a 1080i/16:9 picture. If this is the case with your TV not allowing zoom of any 1080i/16:9 content, it would explain why you are unable to correct the black bars.
That makes sense. There are a couple other stations that do the same thing. The TV setup says that those stations affected are already in "full" mode, much the way stations that broadcast in 16:9 also say "full". There is, of course, no reason to change the format for a program broadcast in 16:9 to anything different. So if, as you say, the ones that look like they are in 4:3 ration are actually in full screen with embedded black bars, that would explain why I can't change it.
I'll go with that thinking unless someone else has any other ideas that make more sense. Thanks for your help.