Scientific Atlanta 3270HD - Manual (Page 11)

11
What are the Differences Between Standard TVs and HDTVs?
• An HDTV is 1/3 wider than a tradi-
tional TV. The HDTV aspect ratio is
usually 16:9 (compared to 4:3 for
SDTV).
• HDTV uses a much finer resolution to
create the TV picture—up to 1125 lines
for HDTV, as compared with 525 lines
used in SDTV. This means that the
resolution for HDTV can be up to
1920x1080 pixels, as compared with
720x480 pixels for SDTV.
• In the USA, HDTV is always broadcast
with digital signals. SDTV is currently
broadcast in both digital and analog.
(However, HDTV and digital SDTV do
not use the same digital signal.)
• Generally, all HDTV-ready monitors or
integrated HDTV sets are capable of
supporting an SDTV 480i or 480p
signal. Not all HDTV monitors support
both 720p and 1080i HDTV signals.
For instance, some plasma displays
only support 720p.
The aspect ratios differ because the
television industry manufactures both
standard and wide-screen HDTVs, to
appeal to consumer viewing preferences.
Wide-screen TVs differ in the way that they
display standard-screen programming. You
can view the program in “pillarbox” format
(surrounded by blank bars), or you can
stretch or zoom the picture to fill your
HDTV screen.
Your set-top allows you to choose the way
you want to view standard-width program-
ming on your wide-screen TV. See
Selecting Your Picture Size and Format
on page 18.
Why are some HDTVs 4:3 Aspect Ratio and Others are 16:9?