720p Vs 1080i HDTV

720p vs. 1080i is worthy of concern? Yes and no. If you are a consumer looking for a new TV, you can happily ignore the 720p vs 1080i debate because every TV which is described as HDTV or HDTV Ready is required to support both formats.

NOTE: You must be aware that if a lot of TVs which support 1080i have fewer than 1080 lines and so scale the 1080 signal down. This is not a huge issue because even reduced 1080i is far ahead of a regular NTSC signal. It is good to keep in mind that more expensive HDTVs tend to have better scalers than cheaper, and this may be a problem.

However, for broadcasters, it is a hot topic. Should they broadcast 1080 lines of interlaced video or 720 lines progressive scan? They could just broadcast two signals, one in each format, but would use a huge chunk of bandwidth and be hugely expensive for very little gain.

To answer the question, it is important to understand the difference between 720p vs 1080i. A 720p signal is made up of 720 horizontal lines. Each image is displayed in full-screen for 1/30th of a second. This is known as progressive scan (hence the 'p') The quality is like watching 30 photographic images a second on TV. A 1080i signal comprises 1080 horizontal lines but all lines are not displayed on the screen simultaneously. Instead, they are interlaced (hence the 'i'), ie every other lines is displayed for 1/60th of a second and then the alternate lines are displayed for 1/60th of a second. Thus, the frame rate is still 30 frames per second, but each image is divided into two areas, that is when your brain unconsciously.

Most of the time interlacing works fine, but for fast moving images like sports such as baseball and hockey it can cause problems which manifest themselves in a "stage effect" on the screen. Progressive Scan Signals do not have this problem and are therefore better suited to sports.

ESPN puts it this way: "progressive scan technology produces better images for guidance in fast moving sports television. In simple terms, with 104 fastballs mph in baseball and 120 mph shots on goal in hockey, line by line progressive scan technology better captures the inherent fast action sport. For ESPN, progressive scan technology makes perfect sense.

Bottom line? For us as consumers 720p vs 1080i debate is not just to address it, so you can relax and concentrate on all other criteria for your list when you buy your next HDTV.