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.
So how do HDTV and full HDTV differ from analogue TV? Certainly the most obvious feature is the resolution. Standard HDTV has a resolution of 720i or 720p and full HDTV has 1080i or 1080p. The 'p' signifies progressive scanning versus interlaced, i.e. all the vertical scans are done at the same time. With a 16:9 aspect ratio in HDTV this results in 1520 x 720 pixels for standard HDTV and 1920x1080 pixels for full HDTV.
The full HDTC is the product that is most favourable, but on TVS with a smaller screen than 42 inches, the difference in the resolution between the standard and full HDTVs isn't noticeable. Therefore, any TV that has a smaller screen than 42 inches is only available in standard HDTV. So, if you want to have full JDTV, you will need to purchase a TV that is 42 inches or larger.
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 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.
Of course full HDTV plasma is not perfect. The power requirements can be as high as 500 watts for some large screen versions and because the screen is made of glass, glare can be a problem. Plasma displays are heavier compared to their LCD counterparts but can be wall mounted.
Full HDTV LCDs have the same resolution, 1080p, as plasma HDTV. Initially, slow response times in LCD sets could result in ghosting on fast-moving images. However, refresh rates have decreased to about 2 ms with a 240Hz refresh rate. The contrast ratios have also been improved to 30K. Full HDTV LCD's are less expensive for the high-end systems necessary for full HDTV.
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.
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.
So how do HDTV and full HDTV differ from analogue TV? Certainly the most obvious feature is the resolution. Standard HDTV has a resolution of 720i or 720p and full HDTV has 1080i or 1080p. The 'p' signifies progressive scanning versus interlaced, i.e. all the vertical scans are done at the same time. With a 16:9 aspect ratio in HDTV this results in 1520 x 720 pixels for standard HDTV and 1920x1080 pixels for full HDTV.
The full HDTC is the product that is most favourable, but on TVS with a smaller screen than 42 inches, the difference in the resolution between the standard and full HDTVs isn't noticeable. Therefore, any TV that has a smaller screen than 42 inches is only available in standard HDTV. So, if you want to have full JDTV, you will need to purchase a TV that is 42 inches or larger.
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 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.
Of course full HDTV plasma is not perfect. The power requirements can be as high as 500 watts for some large screen versions and because the screen is made of glass, glare can be a problem. Plasma displays are heavier compared to their LCD counterparts but can be wall mounted.
Full HDTV LCDs have the same resolution, 1080p, as plasma HDTV. Initially, slow response times in LCD sets could result in ghosting on fast-moving images. However, refresh rates have decreased to about 2 ms with a 240Hz refresh rate. The contrast ratios have also been improved to 30K. Full HDTV LCD's are less expensive for the high-end systems necessary for full HDTV.
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.
About the Author:
James Junior writes informative articles about Full HD high definition TV including information about Full HD high definition LCD TV
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