Ray Melnik
Agent
- Joined
- Feb 18, 2002
- Messages
- 33
HDTV Overview
High-definition television (HDTV) offers advantages today while providing incredible potential for the future. Although it won't reach its full potential for some time there are many reasons why you should consider being HDTV-ready when you make your next viewing entertainment purchase.
The standards for HDTV are still being worked out, but it is generally agreed that in order to be considered HDTV or HDTV-ready, the monitor or projector must display either 720p or 1080i vertical resolution and be wide-screen 16:9.
Let's see what that means and compare it to the dominant standard for TV today.
The original National Television Standards Committee (NTSC) settled on an aspect ratio of 4:3 with just over 480 lines for the picture, using interlaced resolution. The 4:3 means that the screen is 4 units wide for every 3 units tall. Interlaced means that half the lines are displayed for 1/60th of a second and the other half for 1/60th of a second. This means the full frame is displayed in 1/30th of a second.
Compare that to the Advanced Television Systems Committee (ATSC) standards for HDTV with 1080i displaying 1080 lines interlaced or 720p (progressive scanning) with 720 lines displaying the full frame at once in 1/30th of a second. The 16:9 means that the screen is 16 units wide for every 9 units tall. This gives you a closer approximation to the wide-screen in your local movie theater.
The ATSC is responsible for digital television standards and development including 18 formats for digital television.
When looking at the picture quality it is also important to look at the pixel size. The old NTSC format uses pixels that are rectangular. They are a little taller than they are wide. The HDTV format uses square pixels, which helps create a sharper image. They are also four and one half times smaller than the old NTSC format. This gives you four and one half times better detail for a given area.
One of the best reasons to be HDTV-ready is the DVD. DVD looks great on a regular TV but it looks even better on your HDTV-ready display. DVDs are growing faster in popularity than VHS or even color TV ever did and is proving to be the largest motivating factor for buying HDTV-ready today.
HDTV programming
Choices for HDTV programming are growing but there are many things that have to be hammered out between the various entertainment providers. Although HDTV will be broadcast on UHF channels, many households rely on satellite or cable. There is no mandate for digital conversion for cable providers but many are transitioning to digital on a voluntary basis or because of franchise agreements.
HDTV can be broadcast over an analog signal and is currently broadcast this way in Japan. The US and Canada have decided to switch over to HDTV and digital broadcasting at the same time. Interactive TV and the ability to optimize bandwidth are just two advantages. Digital signals do not cause ghosting or reduction in picture quality because of distance such as with analog signals.
HDTV sound
HDTV also uses Dolby A3 as its sound standard, also known as (5.1) surround-sound. Dolby A3 gives you three front channels left, center and right as well as rear left and right. The .1 represents the low-frequency subwoofer channel, which accents the low-frequency effects that help you feel the sound. Home theater sound systems are continually lowering in price and compliment the HDTV picture to complete your system.
Connections
When considering your HDTV system you must check the video connections for compatibility. Composite or S-Video connections cannot adequately pass the resolution associated with HDTV so it is important to choose a display system with component, RGB or 15 pin D-shell connections.
High-definition television (HDTV) offers advantages today while providing incredible potential for the future. Although it won't reach its full potential for some time there are many reasons why you should consider being HDTV-ready when you make your next viewing entertainment purchase.
The standards for HDTV are still being worked out, but it is generally agreed that in order to be considered HDTV or HDTV-ready, the monitor or projector must display either 720p or 1080i vertical resolution and be wide-screen 16:9.
Let's see what that means and compare it to the dominant standard for TV today.
The original National Television Standards Committee (NTSC) settled on an aspect ratio of 4:3 with just over 480 lines for the picture, using interlaced resolution. The 4:3 means that the screen is 4 units wide for every 3 units tall. Interlaced means that half the lines are displayed for 1/60th of a second and the other half for 1/60th of a second. This means the full frame is displayed in 1/30th of a second.
Compare that to the Advanced Television Systems Committee (ATSC) standards for HDTV with 1080i displaying 1080 lines interlaced or 720p (progressive scanning) with 720 lines displaying the full frame at once in 1/30th of a second. The 16:9 means that the screen is 16 units wide for every 9 units tall. This gives you a closer approximation to the wide-screen in your local movie theater.
The ATSC is responsible for digital television standards and development including 18 formats for digital television.
When looking at the picture quality it is also important to look at the pixel size. The old NTSC format uses pixels that are rectangular. They are a little taller than they are wide. The HDTV format uses square pixels, which helps create a sharper image. They are also four and one half times smaller than the old NTSC format. This gives you four and one half times better detail for a given area.
One of the best reasons to be HDTV-ready is the DVD. DVD looks great on a regular TV but it looks even better on your HDTV-ready display. DVDs are growing faster in popularity than VHS or even color TV ever did and is proving to be the largest motivating factor for buying HDTV-ready today.
HDTV programming
Choices for HDTV programming are growing but there are many things that have to be hammered out between the various entertainment providers. Although HDTV will be broadcast on UHF channels, many households rely on satellite or cable. There is no mandate for digital conversion for cable providers but many are transitioning to digital on a voluntary basis or because of franchise agreements.
HDTV can be broadcast over an analog signal and is currently broadcast this way in Japan. The US and Canada have decided to switch over to HDTV and digital broadcasting at the same time. Interactive TV and the ability to optimize bandwidth are just two advantages. Digital signals do not cause ghosting or reduction in picture quality because of distance such as with analog signals.
HDTV sound
HDTV also uses Dolby A3 as its sound standard, also known as (5.1) surround-sound. Dolby A3 gives you three front channels left, center and right as well as rear left and right. The .1 represents the low-frequency subwoofer channel, which accents the low-frequency effects that help you feel the sound. Home theater sound systems are continually lowering in price and compliment the HDTV picture to complete your system.
Connections
When considering your HDTV system you must check the video connections for compatibility. Composite or S-Video connections cannot adequately pass the resolution associated with HDTV so it is important to choose a display system with component, RGB or 15 pin D-shell connections.