Why do shows on network tv seemed "zoomed in"?

Question

I've notice that shows on ABC, NBC and PBS (maybe CBS too) appear to be zoomed in as the on-screen text is cut off. It is not a problem with the tv set as this does not happen with videos and on cable channels. Any ideas as to what is going on?

Answer 1

I've noticed the same thing.  In fact, during the Academy Awards shows, some of the captions describing the clips were cut off.  And I have a widescreen TV, so I could see that the problem wasn't in my set - it was in the signal coming to it from the cable.

I suspect that someone - the network (less likely) or our local stations (more likely) is getting a signal that is meant to be seen on a normal (4:3 ratio) TV in a "letterboxed" format.  But they decide that it should not have the black bars on the top and bottom, so they "zoom" it to fill the screen vertically, not noticing that this cuts off parts of the display.