High Definition Television (HDTV)

With the transmission of High Definition (HD) Television services now prevalent  investment in a good HD TV makes more sense now than it did a couple of years ago so what do you look out for; what makes a good HDTV and what essentials will help you future proof the Television to ensure this major investment remains viable for a good length of time.

Firstly there are two schools of thought as to the bells and whistles that a new HD TV needs one spouts buy only those features available now and the other preaches buy for the new functions that are just around the corner. Needless to say either camp will be able to claim victory at some point in the future as various functions offered either fall by the wayside of consumer demand or are swept along with feverant purchases

There are many types of HD TVs available, Tube based aka Cathode Ray Tube (CRT), Plasma TV, Liquid Crystal Display (LCD TV) and Back screen projection TVs to name but a few.

If you are looking for a replacement TV you should get one that is Digital Ready - check for the Symbol , Digital TV is happening, it has been committed to and all the various TV regions will start shutting their old analogue signals down from 2008 and all will be turned off by 2012. Retailers left holding analogue TVs will be pushing very good deals to shift these so be sure if tempted that you could live with having to have a separate box to receive your signal as well as the TV.

So what is High Definition Television? Basically it is all about the number of lines transmitted by the broadcasters, the Standard definition broadcast today in the PAL standard is 625 lines, the older readers will remember the old UHF signal which broadcast with 405 lines. The American standard NTSC uses 525. All these standards were viewable and often there will little need for greater definition as older screens were not large and thus a high definition was not necessary, however as technological advances have allowed greater screen size coupled with greater consumer demand the display units used for TV have got bigger which in turn has led for the demand to increase the definition to allow larger screens to display the picture without having to do weird and wonderful things to “fudge” the picture in an attempt to make it look sharp and detailed.

High Definition will broadcast in either 720 or 1080 lines obviously the more lines the greater the definition and the greater the definition the greater the size of screen can be used without a perceived degradation in picture quality.

There is also another thing to take into account with HD TV and this is the Frame rate this is quoted in Frames per Second (fps) however it also can use two types of standards Progressive (p) or Interlaced (i) effectively progressive is the frame rate quoted where as interlaced is half the frame rate and it doubles up or “interlaces” the lines on two fields on screen to improve the quality of the picture.

There is slight variance in how manufacturers state what their TVs do within the specifications however it is common to see 1080i or 720p meaning 1080 lines interlaced and 720 lines progressive respectively. Alternatively when frame rate is included they would state 1080/50i or 720/60p indicating 50 interlaced frames per second or 60 progressive frames per second respectively. Remember that as the interlaced standard doubles up the actual frame rate of 50i will be 25 frames per second.

Only the 1080 specification has interlaced options so manufacturers may drop the p when quoting 720 specs.