Since the federal regulation of mandatory DTV (digital television) signal, the subject of full HDTV (full high definition television) has become a more popular topic of discussion and has become more of an interest to the public. With the digital changeover, now everyone has access to HDTV signal. However, an HDTV display is still necessary in order to view high definition no matter what type of signal you have (cable, antenna, or satellite).
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.
HDTV and full HDTV are different from analogue TV due to the resolution of each. The standard HDTV has a resolution of 720i or 720p while a full HDTV has a resolution of 1080i or 1080p. The "p" instead of the "i" stands for progressive scanning. This means that the vertical scans are done simultaneously. Using a 16:9 aspect ratio, the standard HDTV is has 1520 x 720 pixels and the full HDTV has 1920 x 1080 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.
The three options available for full HDTV are rear projection, full HD plasma, and full HD LCD TV. The rear projection TVs are still available, but the demand for them isn't great and a lot of TV makers aren't producing them any longer. Therefore, you should stay away from the purchase of these. This leaves you with the other two options. When deciding between the other two, response time, contrast ratio, and color reproduction should be considered.
Full HDTV plasma displays are bright, have a wide color range, and can be produced in fairly large sizes, up to 58 inches is commercially available. Because the display panel is only about 6 cm (2.5 inches) thick, the overall thickness is about 4 to 6 inches. Contrast ratios are as high as 50K to 100K are claimed but, in reality, the highest available in stores is 30K with response times at 0.001 milliseconds and refresh frequencies of 600 Hz. Fast response times make plasma TV's ideal for fast motion video (films or sports viewing). Plasma screens also are said to have better color reproduction than LCDs and to have a wider viewing angle.
One disadvantage is the power requirements in a plasma TV. The requirements can be as high as 500 watts. In addition, plasma TVs are traditionally heavier than LCD displays. However, the plasma can be mounted on a wall and the LCD display can't.
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.
With the exception of resolution, the other features, advantages and disadvantages of each of these types of TVs depends on what's most important to you. In closing, if you have the extra money to spend, full HDTV is the optimum choice in TVs. When endeavouring in an entire home theatre, you should be sure that your full HDTV is compatible with the rest of the system. - 32388
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.
HDTV and full HDTV are different from analogue TV due to the resolution of each. The standard HDTV has a resolution of 720i or 720p while a full HDTV has a resolution of 1080i or 1080p. The "p" instead of the "i" stands for progressive scanning. This means that the vertical scans are done simultaneously. Using a 16:9 aspect ratio, the standard HDTV is has 1520 x 720 pixels and the full HDTV has 1920 x 1080 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.
The three options available for full HDTV are rear projection, full HD plasma, and full HD LCD TV. The rear projection TVs are still available, but the demand for them isn't great and a lot of TV makers aren't producing them any longer. Therefore, you should stay away from the purchase of these. This leaves you with the other two options. When deciding between the other two, response time, contrast ratio, and color reproduction should be considered.
Full HDTV plasma displays are bright, have a wide color range, and can be produced in fairly large sizes, up to 58 inches is commercially available. Because the display panel is only about 6 cm (2.5 inches) thick, the overall thickness is about 4 to 6 inches. Contrast ratios are as high as 50K to 100K are claimed but, in reality, the highest available in stores is 30K with response times at 0.001 milliseconds and refresh frequencies of 600 Hz. Fast response times make plasma TV's ideal for fast motion video (films or sports viewing). Plasma screens also are said to have better color reproduction than LCDs and to have a wider viewing angle.
One disadvantage is the power requirements in a plasma TV. The requirements can be as high as 500 watts. In addition, plasma TVs are traditionally heavier than LCD displays. However, the plasma can be mounted on a wall and the LCD display can't.
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.
With the exception of resolution, the other features, advantages and disadvantages of each of these types of TVs depends on what's most important to you. In closing, if you have the extra money to spend, full HDTV is the optimum choice in TVs. When endeavouring in an entire home theatre, you should be sure that your full HDTV is compatible with the rest of the system. - 32388
