Before buying a new flat panel HDTV display, one important thing to check is the screen resolution. You often see the numbers 720p, 1080i or 1080p in HDTV display specs and may wonder what they mean and how they translate to picture quality. The sales guy may lure you to buy the set with the highest specs but do you really need to? This article will try to answer these questions and provide us basic knowledge on display resolution.

Resolution refers to the number of pixels available on the picture frame. The higher the number of pixels, the better the quality of the picture is. Standard Definition Television or SDTV resolution is either 480i (NTSC standard) or 576i (PAL standard). 480i means there are 720 x 480 (W x H) pixels on the screen while there are 720 x 576 (W x H) pixels for 576i. The letter “i” refers to interlaced scanning wherein a picture image is actually formed by two alternating frames. This is based on analog interlaced scanning technology wherein odd and even interlaced frames simulate a complete picture image.

Enhaced Definition Television or EDTV is an enhanced version of SDTV. It is either 480p or 576p. The letter “p” referes to progressive scanning wherein there is one complete picture frame displayed at any given instant. This technology is similar to movie film technology, in which the eyes perceived moving images from progressively displayed picture frames.

HDTV resolution starts at 720p, which is equivalent to 1280 x 720 (W x H) pixels. The next is 1080i, which is equivalent to 1920 x 1080 (W x H) pixels. The highest HDTV resolution format is 1080p, which is better known as “Full HD.” This has twice the resolution of 1080i because one complete 1920 x 1080 picture frame is displayed at any given time. The resolution formats discussed can also be preceded by the following numbers: 50i, 25p and 50p for PAL countries and 60i, 30p and 60p for NTSC countries. 60i means there are 60 interlaced frames displayed per second while 30p means there are 30 progressive frames displayed per second. A variant, 24p, is used to display film-like images because movie film is displayed at 24 frames per second.

HDTV, because it contains a greater number of pixels, offers far better picture quality than analog TV and SDTV. If you are considering to buy a new television set, there is no other way to go but to choose HDTV. But which should you select between the two popular HDTV resolutions, 720p or 1080p? There is actually not much difference based on what the eyes can see, particularly in screen sizes less than 50 inches. The difference in picture quality will only be noticed at larger screen sizes. If you are on a tight budget and needs only a small display, considering 720p is not a bad idea. But if you’re looking for screen sizes more than 50 inches, say for home-theater systems, better go 1080p or Full HD.