When talking about HDTV, the quality of the picture (or high resolution) is the main point. Anyone who chose to purchase or obtain an HD converter box still has an analogue picture on a CRT screen. The resolution of an NTSC-analogue TV described as 480i. The “i” in the description refers to the word “interlaced”. The reason why is because the CRT tube in the analogue television only 240 horizontal lines available, but the television camera has 480 lines. Therefore, in order to present the look of a more vertical resolution, the television signal is interlaced. If you consider the aspect ratio of 4:3, using basic mathematics, you can see why the analogue TV resolution can be depicted as 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’20 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.
There are currently three options in screen technology for full HDTV: rear projection HDTV, full HD plasma, and full HD LCD TV. Though rear projection televisions are still available, the demand and popularity of them seems to be decreasing. For that reason, many manufacturers aren’t even making them anymore. Therefore, it’s advised to choose between the two remaining options. Other things to consider when choosing a new television are response time, the contrast ratio, and color reproduction qualities.
Features of a full HDTV plasma screen include a wide range in color, great brightness, and very large screens. The display screens can be made up to 58 inches. Also, since the display panel is only 2.5 inches thick, the TVs are only around 4 to 6 inches thick. Claims of contrast ratios in plasma televisions are as high as 50K and even 100K, but the highest contrast available is 30K. The response time is a very quick .001 milliseconds and the refresh frequencies are 600 Hz. Reasons to choose a plasma screen over an LCD display would be better color reproduction, a wider viewing angle, and fast response time. Response time can make a difference with fast moving images in such cases as watching sports and action.
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.
James Junior writes about led television and philips full hd tv
