What is HDTV really all about? What's new, and why is it better? The best way to make a comparison between standard definition television (SDTV) and high definition television (HDTV) is to consider today's popular digital cameras. Some years ago, when digital cameras first appeared on the consumer market, a popular digital camera featured a 1.6 Mega Pixel (Mpix) image sensor. At that time, 1.6 Mpix was considered high quality. Today, one can easily find 5 and 6 Mpix cameras with far better image quality for a lot less money.
In a similar way, HDTV delivers significantly more resolution than SDTV. For example, a 1080i HDTV signal offers about six times the resolution of a conventional 480i SDTV signal. HDTV also features a wider (16:9) aspect ratio format that more closely resembles human peripheral vision than the (4:3) aspect ratio used by conventional TVs in the past. Furthermore, HDTV is based on a system of 3 primary image signal components rather than a single composite signal, thus eliminating the need for signal encoding and decoding processes that can degrade image quality. Perhaps the biggest advantage over the old analog SDTV system is that HDTV is an inherently digital system. If installed properly, digital HDTV can provide the ultimate in pristine image quality, but there are many factors that must be considered, as we shall see.