HDTV Projection or otherwise will soon be your only choice

Choosing your next TV can be a real challenge given the wide ranging choices avaialable and the often confusing terms used to ascert one makes dominance over its competitor. Ultimately your choice will be bourne out of visiting your nearest outlet and visually making the comparison for yourself.

Todays market place is consolidating the high quality standards brought about by HDTV or High Definition Television, but what exactly is it and what should you be on the look out for when considering a purchase?

Here are some points of reference that should assist you in your purchasing decision.

First of all be very careful when considering what is described as a HDTV ready TV. The inference being that the set is fully ready to provide you with the best viewing quality when broadcasts are more readily available in your area. This is not necessarily the case and where knowing some of the questions to ask can be a real help.

What is the difference between a traditional TV, DTV, and a HDTV?

The predecessor to Digital Television was the analogue TV which had poorer resolution and needed a good strong signal to deliver its best possible picture quality. Anything other than top notch signal quality caused a progressive degrading of the image (often reffered to as 'snow' (actually 'noise' that got worse the weaker the signal became). These sets were also prone to ghosting caused by slight shifts in the arrival time of elements that made up the signal.

Digital television (DTV) eliminates this by encoding the signal 'digitally' which allows the technology to deploy various techniques to adjust for varying conditions. DTV signals provide a great improvement over their analogue conterparts with a picture that is in comparison snow free and of much more consistent and higher quality.

High-Definition Television takes this technology one step further resulting in high-quality pictures. It is important to note that some TV’s will be classified as DTV, SDTV or EDTV, and some are HDTV. Don’t let the salesperson convince you that a DTV, SDTV or EDTV are the same as a HDTV; this simply is not the case and sadly all too often the salesperson is not trained sufficiently to give you the expert advice needed.

So lets compare some factors that will help define what HDTV delivers.

Display Type and Format

Direct View – This is the traditional TV. Sizes range from 30” to 40”.

Projection Rear – Image is projected and reflected onto the screen from behind the screen. Sizes range from 30” to 70”.

Projection Front – Two piece system composed of a projector and a screen. The ultimate home theater system.

Wide Screen – Great for high definition programming. 16:9 ratio width to height.

Traditional Square Screen – Best for analog. 4:3 ratio width to height

SDTV – Digital television (Standard-Definition Television - 640 x 480 pixels [dots making up the image])

EDTV (Enhanced-Definition Television) sets — typically flat-panel LCD or plasma models with 852 x 480-pixel resolution

HDTV – This is the only true "HDTV." 16:9 ratio - 1280 x 720 or 1920 x 1080  pixel resolution

Types of Systems

Integrated System – This is the ultimate, complete HDTV system. The HD receiver is built-in which requires simply connecting the TV to the cable or satellite source.

HDTV-Capable  – Requires an external HD receiver (either purchased separately or obtained through your cable or satellite provider) in order to view HDTV programs. Without this receiver, the TV functions like a traditional analog TV. When selecting the external HD receiver, verify that it is compatible with your HDTV as there are different types.

HDTV-Ready – This is not necessarily the same as HDTV-Capable. If a TV claims to be HDTV-Ready it should already have a HDTV tuner built in, you should verify that it can actually display true HDTV and be careful to ask which line rates it supports. 

Screen Resolution

A TV picture is formed from a number of horizontal lines the more 'lines' the better the picture. These lines are referred to as the “vertical resolution” because the lines are counted down from the top of the screen. There are two ways to display the lines: interlaced and progressive. Progressive is the newer technology and is used only by DTV. However, some DTV’s also use interlace rather than progressive. Progressive provides a smoother motion in moving images as well as an overall brighter, sharper picture. It also eliminates “flickering” which is noticeable in interlaced displays.

Standard TV has a vertical resolution of 480 lines. This means that 480 lines are used to make the visible image. This is identified as: 480-i (where “i” stands for interlaced).

The most popular HDTV's have a vertical resolution of 720-p (where “p” stands for progressive) and 1080-i. Both of these resolutions produce excellent images and its best to view both types before making your final decision.

Another feature regarding resolution is “scaling.” This refers to the TV’s ability to scale the image in order for the resolution to be viewed appropriately and is necessary because some of the broadcast material varies in its format and so the scaling ability makes the image as large as possible relevant to your display without distorting it in either the horizontal or vertical direction - the proportions remain the same.

Even if HDTV programming availability is still limited in your area, you shouldn't rule out an HD-capable TV. These sets can greatly improve your viewing experience even if you don't watch any HDTV programs. All HDTVs and HDTV-ready TVs include special upconversion circuitry to give non-HD signals (DVD, antenna/cable, digital satellite, etc.) a cleaner, smoother look and is a very noticeable improvement.

Audio

Audio delivered 'as is' from the television is quite adequate for many, however HDTV's deliver  a digital output, through which they can send a Dolby® Digital encoded bitstream. By making a single-cable digital connection to your A/V receiver, you can enjoy the crystal-clear Dolby Digital sound that is standard on HDTV broadcasts.