A popular topic in televisions nowadays is full HDTV (full high definition television). This is due to the full changeover of digital television (DTV) signal on June 12, 2009. With this transition complete, everyone has access to HDTV signal. However, not everyone has HD display because in order to get it, you must have an HDTV display television.
The main advantage and interest in regards to HDTV is the high resolution. If you chose to go with an HD converter box, your television still has an analogue picture on a CRT screen. The resolution of an NTSC-analogue television is called 480i; the “i” meaning “interlaced”. This means that since there are only 240 horizontal lines available in the CRT tube and the TV camera has 480 lines, every other line is scanned at the same time for 1/60th of a second. Then the other lines are scanned. So, to portray a more vertical resolution, the TV signal is interlaced. With an aspect ratio of 4:3, the analogue TV resolution is 640 x 480i.
The resolution of JDTV and full HDTV are what make them different from analogue TV. The full HDTV resolution is 1080i or 1080p. The standard HDTV has a resolution of 720i or 720p. The “p” stands for progressive scanning, meaning that the vertical scans are done at the same time instead of interlaced. With an aspect ratio of 16:9, the full HDTV has 1920 x 1080 pixels while the standard HDTV has 1520 x 720 pixels.
Full HDTV, 1080p, would seem the product of choice; however, for a TV smaller than 42 inches the difference between standard and full HDTV cannot be seen. Consequently, these smaller TV’s are available only in standard HDTV, either 720i or 720p. To enjoy full HDTV a 42 inch or larger screen is necessary.
Three choices of screen technologies are available for full HDTV. These are rear projection HDTV, full HD plasma TV and full HD LCD TV. Rear projection HDTVs are still available but this technology appears on the decline with many manufactures dropping out of the market. Therefore, one is left with full HD plasma TV and full HD LCD TV to choose between. Since a resolution of 1080p is assumed, other factors affecting image quality to consider are response time and refresh rate, contrast ratio and color reproduction.
Full HDTV plasma screens have a broad range in color, are very bright, and can have very large screens. Display screens of full HDTV plasma TVs can be up to 58 inches in size. Since the display panel is only about 2.5 inches thick, the televisions are only about 4 to 6 inches thick. Though there are claims of contrast ratios as high as 100K in plasma TVs, the highest contrast currently available in stores is 30K. The response time is .001 milliseconds while the refresh frequencies are 600 Hz. The advantages of a plasma TV over an LCD are that the screen has a better color reproduction and also has a wider viewing angle. Because of the fast response time, plasma TVs are great for viewing fast moving film such as sports.
However, the power requirements for a plasma TV can be as high as 500 watts. Also, plasma televisions are heavier than LCDs; however, plasma screens can be mounted on the wall.
Full HDTV LCD displays have the same resolution as plasma full HDTV displays, but the LCD displays have a slower response time (2 milliseconds). This could result in ghosting during fast moving images. The refresh frequency of an LCD display screen is 240 Hz, but the contrast ratio has been improved so that it’s the same as the plasma screen (30K). Though there are some differences in response time and refresh frequencies, LCD TVs are less expensive than plasmas.
Other than resolution, the other features of the two full HDTV options are more up to interpretation and the desire of the consumer. Ultimately, full HDTV is the best choice, taking into consideration the extra cost. However, be careful to make sure that if you’re looking into an entire home theatre that your full HDTV is compatible with the system.