Archived from groups: alt.tv.tech.hdtv (
More info?)
charper1 wrote:
> If you have a standard analog TV, you'll see TV shows displayed in 480i
> resolution. The 480 refers to the number of horizontal lines that make
> up the picture. The "i" means interlaced, which means that half of the
> lines are drawn in one 1/60th-of-a-second pass, then the other half of
> the lines are drawn in another 1/60th-of-a-second second pass, to draw
> the "full" picture every 1/30th of a second.
>
> There are two DVD resolutions. The first is 480i, which uses the
> interlaced method to draw the images onscreen. The second is 480p, also
> known as progressive scan DVD. Progressive scan means that all of the
> lines are drawn sequentially and in one pass, which creates smoother
> images than the 480i picture. The progressive scan 480p image isn't
> high definition, but it's the next best thing.
>
> The main resolutions used to deliver HD programming are 720p and 1080i.
> The 720p picture is drawn with the same method we discussed for
> progressive scan DVD, giving you a picture with 720 horizontal lines,
> each consisting of 1280 pixels. The 1280 x 720 resolution gives you the
> 16:9 wide screen aspect ratio that defines HD. The 1080i picture is
> drawn in two passes using the interlaced method. However, because there
> are far more lines in a 1920 x 1080 picture, the visibility of the lines
> is reduced and the level of detail is increased. Some say 720p does a
> better job with fast-moving images, while 1080i is the highest possible
> HD resolution in terms of detail. At the end of the day, both
> resolutions deliver a superior picture - nothing else comes close.
>
> SO I JUST PLUG HD PROGRAMMING INTO MY TV AND I SEE THE HIGHER
> RESOLUTION, RIGHT?
>
> Not so fast. There are two issues when it comes to resolution: the
> resolution of the signal being sent to the TV, and the resolution that
> the TV is capable of displaying. This is where the native resolution of
> your TV comes into play. The native resolution describes the amount of
> vertical and horizontal pixels your TV can show. To display true 1080i
> HD as it is intended to be seen, you need an HDTV with a native
> resolution of 1920 x 1080 or higher. Many HDTVs can handle a maximum of
> 720p at full resolution, and 1080i programs are converted to fit their
> screen. In addition, there are digital TVs that have lower than 1280 x
> 720 native resolution, but are able to convert and display both 720p
> and 1080i images.
>
> LONG STORY SHORT, WHAT DOES ALL OF THIS MEAN TO ME?
>
> It means that you can read about HD resolution all the live-long day,
> but the best way to understand HD resolution is by watching it. Go to
> an electronics store and take a look at what's playing on the HDTVs.
> Find out what the resolution of the programming is (Discovery HD
> Theater, an electronics store favorite, is 1080i). Then decide what
> degree of resolution is satisfactory for your viewing needs. Perhaps
> you'll only be satisfied with a top-of-the-line model that allows for
> maximum HD resolution. Perhaps you'll find an HDTV that has a lower
> resolution but looks better to you for other reasons: contrast ratio,
> color temperature, etc. It's time to take another trip down the HDTV
> aisle and see the big picture for yourself.
>
>
Charper -- this is an excellent explanation. I have a related question,
though. My monitor's rez is 1280x720. My DTV tuner can be set up to
output either 1080i or 720p via the DVI port. Which should I set it to?
Will I see any more detail if i set it to 1080i? Or will the monitor
remove the extra detail when it converts the 1080i signal to fit the
native resolution?
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