dish-cable.com

 Home    Site map    Contact    Policy    Links 

Cable and satellite services HDTV 

 

High-definition television (HDTV)

Are you too mystified and intrigued by this new kid on the TV block: high-definition television (HDTV). Expectations run high, but so is the uncertainty - what is really different about it, when compared with standard-definition television (SDTV)?

In simplest terms, while both use digital signal, HDTV uses more pixels (pix-el/ement, physical display unit of image-forming television screen) per given screen area than standard digital television. This results in finer resolution, as well as smoother motion and better color definition. This is especially advantageous with larger TV screen formats, which with standard pixel number have them enlarged enough to cause picture granulation. Due to smaller pixel size, high-definition TV screen has 2-5 better resolution than standard TV.

Compared to a standard (analog) TV, standard digital TV (SDTV) has the same 720x480 pixels resolution, but has the advantage of progressive (continuous) scanning (denoted 480p), as opposed to inferior alternate line scanning (480i, for "interlaced" scanning) of the analog TV. But even more, digital TV owes its quality to the properties of a digital TV signal, which is code based (binary code, 0,1), thus much less affected by the amplitude loss in transmission. Unlike it, analog TV signal is flow based, and needs to be re-enforced in transmission by a number of amplifiers, creating electronic noise and distortions.

Digital TV signal also can be compressed much more efficiently, allowing for significantly higher channel capacity.

 For TV screens smaller than 27" DTV is as good as HDTV. Larger screens, however, benefit from higher density resulting in smaller pixel size.

High-definition television begins with 1 million pixel level, or 1280x720 pixel screen (also progressive scanning, thus 720p format). The next larger format is 1920x1080, which comes either as 1080i (with interlaced scanning), or 1080p (progressive scanning) format. There are intermediate formats, such as one used in Australia, which is termed HDTV there, and "enhanced digital TV" elsewhere.

While interlaced scanning has the advantage of using only half the bandwidth required by progressive scanning, allowing it to achieve higher resolution than progressive scanning for given bandwidth (due to a higher pixel count possible), its alternate line refreshing mode produces undesirable artifacts and effects, tending to cause eye strain and fatigue. Due to this disadvantage, it was quickly abandoned by the PC industry, and will likely be eclipsed by progressive scanning in the area of HDTV as well.

HDTV comes with wider screen format. Its 16:9 screen ratio is between the nearly square 4:3 ratio of standard television, but not as wide as format used for most movies (from 5:3 to 3:1 screen ratio). It will still some cause cropping, and display black top/bottom bars when playing such movies, although less than standard television. On the other hand, HDTV format will show vertical side bars with some older TV shows and movies.

Although not inherently part of HDTV, it comes with top-notch audio quality (Dolby Digital), superior to standard TV audio. Also, being using digital technology, HDTV offers steady quality and higher reliability.

So, what do you need to be able to watch HDTV? Other than high-definition TV set with high-definition screen and built-in or set-top HD tuner for HD signal processing, you need - of course - HDTV signal itself. This signal can be received either by a standard UHF antenna (for local HDTV broadcasts not transmitted through cable or satellite TV), TV cable (for HDTV from cable TV service) or HDTV-capable satellite TV dish.

While non-HDTV set still can receive HDTV channels, if hooked up with HDTV decoder, you will only have a partially improved picture quality. And vice versa, HD TV set often has standard (analog) signal picture showing worse than on standard TV sets. Part of it is that HDTV sets generally have larger screens, magnifying picture defects, which are rather numerous in the analog mode. Adding to that, the superior screen resolution of an HD television set will often show such defects more clearly than lower resolution standard TV screens.

Nothing is perfect, and that includes HDTV. But if you want large screen television, HDTV is the way to go. Available HD programming is booming, and some technical problems still plaguing the execution will likely be soon remedied. If you are for HDTV, the time is on your side. 

______________________________________________________

Home  Remember those happy days with no cable television, no satellite TV? Only a single analog TV service available, and everything about getting and using it was as simple as: get it, click, go...

Cable or satellite TV?  Which one is better: satellite TV or cable? In most any comparison, the answer seems to depend on whom you ask...

Cable TV  Cable TV is how the television entered American homes. In its early stages, cable TV service was quite different from the modern cable TV we know now...

Direct Broadcast Satellite  Direct Broadcast Satellite (DBS) TV service is a high-powered broadcast service to homes using satellites as the primary form of signal transmission. Its high transmission power makes possible use of relatively small dish antennas for efficient signal reception and utilization. Commercial satellite TV, as we know it, is a DBS service...

Dish Network  Dish Network is the second largest direct broadcast satellite (DBS) service provider in the US. Together with DirecTV, it shares the US home satellite TV market. Dish Network started commercial DBS broadcasting  in 1996, after its first TV satellite - EchoStar I - has been launched in 1995...

DirecTV  DirecTV is a direct broadcast satellite (DBS) service provider, based in Las Vegas, Nevada. Launched in 1994 by Hughes Electronics Corporation, it was the very first high-powered (mini-dish) DBS service in the world...

High-speed INTERNET  Whether you spend many hours browsing the Internet on daily basis, or use it less frequently, high-speed Internet connection appears to be irresistibly convenient. While it comes at added cost, most people find its benefits worth added expense, which can be quite low...

High-definition TV  Are you too mystified and intrigued by this new kid on the TV block: high-definition television. Expectations run high, but so is the uncertainty - what is really different about it, when compared with standard-definition television (SDTV)?...

Satellite Radio  If you like listening to radio programming, satellite radio has some goodies to offer. Great variety of channels, most of them commercial-free, high quality sound when it is needed, possibility to listen to your favored programming wherever you are...

 News Wire  The latest in the satellite/cable industry...

 

 

Home   |   Site map   |   Links   |   Contact   |   Privacy