| THE
HDTV BREAKTHROUGH INTO
TELEVISION COMPUTERS |
Understanding Older Analog TV (return)
Most homes still have the typcial analog television set that has
been in existence for 50 years but the change over to Digital TV (DTV)
and also High Definition Tv (HDTV) is gaining momentum with already
well over a million households having purchased HDTV in the US. It
gets a bit confusing without knowing the difference between analog
TV, DTV and HDTV. Before explaining the difference between DTV and
HDTV one needs to understand what the older analog tv is. Analog television
sets that most people still use today are a completely different system
than digial tv. The video camera taking the picture for analog only
uses 30 frames per second and this is turned into rows of dots known
as pixels which is combined with synchronization signals known as
horizontal sync and vertical sync. These vertical and horizontal rows
are combined in a final signal carrying the proper intensity and color
of each pixel which is known as a composite video signal. This tv
radio signal is carried in what is known as an AM signal wave and
the sound is on a separate signal known as FM radio waves which are
carried on a specfic frequency in the United States know as the VHF
signals on channels 2 through 13 and the UHF on channels 14 through
83.. The electronics in an analog tv picks up these horizontal and
vertical syncs and converts them into a picture and also the sound
on the FM freqency.
The great contrast between analog TV and
HDTV (return)
One can easily be confused to think that if they order a digital
cable tv system package or digital satellite tv package that they
can get digital quality tv pictures and sound. In fact your digital
receiver can receive the digital signal but then it converts back
into an analog signal for your analog tv. The pictures on an analog
tv have 525 lines of resolution every thirthieth of a second with
half the lines displayed in the first half or sixtieth of a second
and the other half displayed in the last sixtieth of a second. This
process is called interlacing and is very hard on the eyes especially
if you look at your tv close up. An analog tv can only display approximately
512x400 pixels which means you have a very blurry picture without
details as is evident when you look up close at these tv pictures.
On the other hand, the older and lowest-resolution computer monitors
display 640X480 pixels which shows significantly greater detail at
this small difference than an analog tv. Now jump to HDTV and you
have 1920x1080 pixels instead of 512x400 and sent at 60 complete frames
per second instead of analog at 30 that are imcomplete interlaced
frames. This is a whole 10 times greater detail and stablity in an
HDTV than an analog tv and is the reason why you have a far more enjoyalbe
and almost real to life three dimenisional like picture that will
be far more enjoyable and easier on your eyes. Also, HDTV has a different
aspect ratio than analog tv. Analog tv has a screen that is 4 units
wide and 3 units high or a 4:3 aspect ratio while HDTV is 16 units
wide and 9 units high (16:9). This aspect ratio of 16:9 is far closer
to the range of human sight so that there is an even greater feel
of being right in the tv scene.
The HDTV computer TV breakthrough (return)
HDTV sets are essentially computer monitors and are already at the
beginning of a new breakthrough known as television computers and
in particular with satellite tv known as PC/Satellite TV. Through
satellite high speed DSL internet you can use your television as a
computer to surf the net and get email. Both DIRECTV and Dishnetwork
provide high speed DSL internet so that you can have these capabilities
with your HDTV.
The difference between DTV and HDTV (return)
So what is the difference between DTV and HDTV? Again, one could
easily assume that when they see a DTV for sale it is just another
word for HDTV. In fact DTV also known as Digital-ready sets have an
analog tuner for displaying the normal analog channels of 3 through
83 in the US but can also display digital images that can hardly be
considered digital. That is because their highest resolution is 480
progressive or non interlaced which means their highest resolution
is 704x480 compared to HDTVs which have 1920x1080. Basically you do
not get high definition resolutions and the TV will be of no use if
in the future you plan to get HDTV programs.
HDTV picture quality (return)
HDTV systems are a whole new tv system that uses far greater resolution
and aspect ratio in the digtal cameras taking the scenes. Also, the
picture sent out from the camera is sent out using completely different
waves that are far superior in quality and quantity. For example,
Digital Satellite Systems (DSS) use microwaves in the “Ku”
band frequency which is much higher than the “C” band
used by Cable TV. Digital signals picked up through the “Ku”
band are MPEG-2 compressed video signals (30:1 bits) which allows
far more channels to be squeezed through without damaging clarity.
So when you have an HDTV and an HDTV receiver your in for a higher
dimension of viewing experience. Satellite TV now offers many High
Definition TV channels and they are adding more programs as soon as
they become available all the time. HDTV gives viewers crystal clear
pictures that are equivalent to theater quality sights and sound with
special Dolby Digital 5.1 channel surround sound. Your D S programming
will be transmitted and received with the same quality that a DVD
player can reproduce movies with big screen quality effects. You need
a HDTV receiver to receive these channels and companies like VMC Satellite
offer these an all their equipment free with a life time warranty.
Most HDTVs do not have a HDTV receiver for satellite tv built into
them which means you have to obtain one for each tv with your satellite
tv system. Dish Network allows up to 2 HDTV recievers free with a
one year committment and purchase of HDTV programming.
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