Ready to purchase HDTV?

So you got the Home Theater bug.  You've heard the buzz, and you're ready to invest in a popcorn popper.  You're dangerously armed with an Dolby Digital/DTS Processor, and ready to rock the house.   You've acquired earth-shattering six speaker surround configuration.   You're gunning for the dream theater and need the perfect video display to wow the audience. 

The simple explanation of Digital TV

Digital TV describes the current crop of higher scan frequency sets.  The designation is bestowed on sets that are able to display progressive signals or include a line doubler to convert the incoming viewable NTSC signal at 480i (interlaced) to 480p (progressive).   Digital TV can be 4:3 or 16:9 aspect ratio.  Ultimately, it is the ability to display the high resolution image defined by the ATSC standards of 1080i or 720p that is the solid foundation of Digital TV.

HDTV or HD-Ready

During the course of shopping for a digital television, the labels HDTV and HD-Ready maybe of some confusion to the consumer.   This HDTV designation signifies that the set has an internal ATSC tuner/decoder, as well as meeting the widescreen specifications often required to be considered a true HDTV.   The sets will meet the requirement to display in 1080i/720p, although it is often the former only.  Very few digital TVs on the market will display in native 720p.   The lack of an ATSC tuner/decoder is not necessarily a negative as many set-top decoders are now available with more features than those included in the integrated HDTV.   The separate purchase of a HD-Ready TV and the external set-top-box often provides flexibility to the consumer to choose one that offers added features such as satellite receiver and the proper output signal.  Most HD-Ready sets will include a high-band component (Y-Pb-Pr) DTV input, although few on the market also offers RGB for this purpose.   There have been much debate between manufacturers as to the aspect ratio specifications of the HDTV designation, and it is now recognized that a true HD set will provide widescreen 16:9 aspect screen.   

The Definition argument

The most common Digital TV's today are based on the Cathode Ray Tube technology.  This is true with both Direct View and Rear Projection sets.  Some purists will argue that the many of today's sets should not be defined as HDTV because the CRT's used cannot define all of the picture elements (pixels) required to display 1920x1080 resolution.  While this is true for most with the exception of 9" CRT based sets, this specification alone should not be the the reason to shun these sets.  While it is true that higher pixel count provides better picture on larger sets, there are variety of smaller TVs that do not require the full 1080 lines to provide incredible picture quality.  These high-fidelity TV's often cost quite a bit more than the sets that use the standard 7" CRT or direct view sets.   If the digital TV that you plan to purchase is bigger than 55", a comparison to a 9" CRT based TV before purchase is highly recommended.

Industry Standards

Due to the confusion in the Digital Television labeling, the Consumer Electronics Association has defined the descriptions for television equipment standards listed below:

High-Definition Television (HDTV): HDTV refers to a complete product/system with the following minimum performance attributes:

• Receiver: Receives ATSC terrestrial digital transmissions and decodes all ATSC Table 3 video formats
• Display Scanning Format: Has active vertical scanning lines of 720 progressive (720p), 1080 interlaced (1080i), or higher
• Aspect Ratio: Capable of displaying a 16:9 image1
• Audio: Receives and reproduces, and/or outputs Dolby Digital audio

High-Definition Television (HDTV) Monitor: HDTV Monitor refers to a monitor or display with the following minimum performance attributes:

• Display Scanning Format: Has active vertical scanning lines of 720 progressive (720p), 1080 interlaced (1080i), or higher
• Aspect Ratio: Capable of displaying a 16:9 image (1)

  (1) In specifications found on product literature and in owner's manuals, manufacturers are required to disclose the number of vertical scanning lines in the 16:9 viewable area, which must be 540p, 810i or higher to meet the definition of HDTV.
  

Enhanced Definition Television (EDTV): EDTV refers to a complete product/system with the following minimum performance attributes:

• Receiver: Receives ATSC terrestrial digital transmissions and decodes all ATSC Table 3 video formats
• Display Scanning Format: Has active vertical scanning lines of 480 progressive (480p) or higher
• Aspect Ratio: None Specified
• Audio: Receives and reproduces, and/or outputs Dolby Digital audio

Enhanced Definition Television (EDTV) Monitor: EDTV Monitor refers to a monitor or display with the following minimum performance attributes:

• Display Scanning Format: Has active vertical scanning lines of 480 progressive (480p) or higher
• Aspect Ratio: None specified
• Audio: Receives and reproduces, and/or outputs Dolby Digital audio
  

Standard Definition Television (SDTV): SDTV refers to a complete product/system with the following performance attributes:

• Receiver: Receives ATSC terrestrial digital transmissions and decodes all ATSC Table 3 video formats, and produces a useable picture
• Display Scanning Format: Has active vertical scanning lines less than that of EDTV
• Aspect Ratio: None specified
• Audio: Receives and reproduces usable audio

What is the benefit of buying DTV for NTSC viewing?

If you do not live in area that offers HD transmission (click here for the listings of HD markets) or you do not subscribe to the satellite services that offer HD programming (requires additional hardware), is there an advantage to purchasing a Digital TV?   The big answer is "YES".   The benefits of digital TV grows with the viewing size.  With smaller direct views, the high resolution capability is not as apparent.  The differences in picture quality is more visible especially when the rear projection DTVs of today are compared to a big screen TV's of the past.  The use of what the television manufacturers often call "progressive scan" which is often more aptly described as "line doubling" often eliminates the distracting black scan lines increasing the appearance of brightness.  The set uses various line doubling algorithms to emulate a "progressive" image, and the use of various scaling techniques often dictate the final image quality of the line doubled image.  It is often common to find an external line scaler in the advanced home theater, such as the iScan Plus marketed by DVDO and Princeton, Crystal Image, or even Faroudja.  It is more common to find these devices in the home theater consisting of a Front Projector driving a large screen.

To 720p or not to 720p

Very few sets offer the ability to scan in 720p (progressive), and much of today's high-definition programs are transmitted in the 1080i (interlaced) format.  As digital engine based sets such as the DLP and LCD TV's become more common, it is expected to adopt and convert incoming signals to the 720p format.  It is inherently simple to do so when using a display technology based on computing monitors, which are natively progressive.  Many consumer electronics manufacturers have decided to forego the more expensive circuitry required to scan in 720p.  There has been much debate as to if this standard should be adopted in our television sets, and it is indeed the preference of many videophiles in viewing film based pictures in the progressive mode, where the movement flows smoother with the full frame based image. 

  

Getting connected  

Display Technology and TV Types

 

• Standard or Widescreen Aspect Ratio

• How to connect your PC to a Digital TV with a Transcoder

• Guide to PowerStrip Custom Timings and Resolutions

• FCC's Digital Television Website.