Scientific Atlanta 3250HD - Manual (Page 26)

Many local TV stations are transmitting digital signals. However,
transmitting a digital signal does not mean transmitting an HDTV signal.
Some stations are using the new bandwidth to broadcast several
standard-definition channels. Most stations however, once they begin
broadcasting in digital, are offering HD content from their parent network
(for example, CBS, ABC, NBC, Fox, WB, UPN, PBS). Are Local TV
Stations
Broadcasting in
HDTV?
Why Are Some
HDTVs 4:3 Aspect
Ratio and Others
16:9? The aspect ratios differ because the television industry manufactures both
standard and wide-screen HDTVs to appeal to consumer viewing
preferences.
• On wide-screen HDTVs, the programming is displayed on the full
screen.
• On standard HDTVs, the programming is displayed in letterbox format
in the middle of the screen. (There are bars surrounding the picture.)
Frequently Asked Questions About HDTV
26
A standard-screen HDTV has
a 4:3 aspect ratio. The screen
is 4 units wide for every 3 units
tall. A wide-screen HDTV is one-third
wider than a standard-screen
HDTV. The screen is 16 units
wide for every 9 units tall.
Aspect Ratio: 4:3
Screen Resolution:
480p or 480i
fills the screen
Aspect Ratio: 16:9
Screen Resolution:
720p or 1080i
fills the screen
——— 4 ——— ———— 16 ————
9 3