Not quite sure what you are trying to say here, ATSC broadcasts (think rabbit ears), cable broadcasts, and satellite broadcasts come in 480i (NTSC-SDTV), 480p(EDTV), 720p(HDTV), and 1080i(HDTV). Whatever panel you choose has a native resolution that generally falls into the 720p range (1280x720, 1366x768, etc) or 1080p range (1920x1080). Any content that is broadcast in 720p or 1080i is considered HD. Using film mode and proper de-interlacing, many 1080i broadcast shows can be displayed on your HDTV as full 1080p.
Further, contrast ratio has nothing to do with the screen resolution (720p vs. 1080p), and more to do with sub-pixel design, backlight technology, and other factors. Most advertised "Contrast Ratios" should be taken with a VERY LARGE grain of salt, as they do not represent real world viewing conditions, and are just marketing jargon.
You may also want to check out a wiki article on how interlaced signals are drawn. Interlaced means that every other line is broadcast in every other field. This means that every 1/59.94th of a second, you will either receive all the odd lines, or even lines of the image on the screen. Lines of video are always drawn from left to right, and top to bottom (some exceptions for MPEG encoded content). 1080i signals are definitely HD and are used by many major networks.
When a show presented in 1080i, the display will de-interlace the 60 fields a second into a 1080p (60 frames per second) signal to fill you 1080p display. This means that anything that is broadcast in 1080i will have to be downscaled to be displayed on a 720p set (meaning that you will lose information).
I am not trying to dog on you, I am just a Electrical Engineer who works in the pro A/V market (video scaler deign) and do not like to see any miss-information being propagated to my fellow Wooters
yazanh28 wrote:So the p stands for progressive as in the pixel lines on the TV are loaded progressively which is much better then when it used to be I or interlaced which means a line on the left loads while a different line loads from the right. The thing that most people don't know about 1080p and 720p is that you can only get 1080p from blu ray movies or upscaled dvds. When you are watching a show on TV that says HD it is actually only 720p which means getting 1080 while only watching television is pretty useless. The only issue is if you upgrade to 1080 your not just paying for 1080 your paying for an increased contrast ratio. So now the question is can someone notice a difference in contrast ratio, the answer is yes to a certain point. I will tell you right now that a contrast ratio of 29,000;1 is horrible in a 47 in even for an lcd. A 42-50 in plasma or led will have a contrast ratio of around 2-3 million to one. Plus the average contrast ratio on a higher end brand LCD will be at least 75 thousand to one.