If your TV doesn't support 1080p...

[Shawn2009]

does it downscale the movie to 480p or can it go to 720p?

[McGarnigal]

Yes, it can do480i/p, 720p, (768p in some tvs) or 1080i, I wouldn't call it downscaling in this instance, sounds worse than it is which is just scaling to your tvs native resolution.

[McGarnigal]

And of course you want to use teh best settings/conections possible, and set your player to output the best resolution your tv can handle. I take it you have a blu-ray player or ps3 and a 1080i or 720p hdtv?

[aramis109]

I had an old set that would do 1080i or 480i/p, but could not do 720p at all. So... if you've got an older set, it'd be a good idea to check before just assuming it will do it.

[lokir1]

In my opinion if the tv is 1080i and capable of 720p set the output of your source components to 720p as a progressive scan picture beats an interlaced scaned picture any day

[RBBrittain]

Originally Posted by lokir1

In my opinion if the tv is 1080i and capable of 720p set the output of your source components to 720p as a progressive scan picture beats an interlaced scaned picture any day

Yes, that is definitely your opinion--not mine. Much like you really can't compare audio formats (MP3 vs. WMA) by bitrates alone (as Microsoft tried in the beginning), "progressive scan is better" only holds true at the same overall resolution (i.e., 1080p vs. 1080i, both 1920 x 1080). If the progressive-scan format has fewer pixels (i.e., 720p is 1280 x 720), it's more complicated than that.

Though it has half the scan lines per frame, 1080i has the exact same horizontal (left-to-right) resolution as 1080p, and requires ZERO pixel interpolation to convert from 1080p (unlike 720p). Most importantly, interlaced scan was designed for CRTs whose phosphors fade more slowly than newer display technologies (LCD, plasma, etc.) made for progressive scan; 1080i on a 16x9 CRT is the closest you can get to 1080p without actually being there.

The correct answer is almost always "your TV's native resolution"; anything else would force a second conversion inside the TV, which is usually a bad thing. (The only major exception is a "choice of lesser evils" situation, like picking 720p or 1080i on a cable box to feed a 1080p TV.)

By stating it's "1080i and capable of 720p", you implied a 1080i-native CRT; in that case you want 1080i, as a 720p input would be converted to 1080i inside the TV. (However, if it's a 4x3 CRT, unless you like super-thin people you should replace it; the scaling needed to letterbox 16x9 images to 4x3 destroys the impact of HD. I know; my first HDTV was a Samsung 4x3 CRT.)

OTOH, if it's anything other than CRT (LCD, plasma, etc.), it's 720p-native (interlaced scan is almost never native on a non-CRT set) and should be set to 720p.