Why do most HDTV's have a 768 native res?

[Pirotic]

One for the video-buffs, but seeing as the two HD standards are 720p and 1080, why on earth do most HDTV's have a native resolution of 768? surely a native resolution of 720 would allow for one to one pixel mapping which would result in a sharper picture. having 768 native resolution just means both the HD standard resolutions need to be re-scaled, why is a bit silly isn't it?

It also leaves me puzzled as to which resolution I should set my PS3 and Xbox360 to. If i run in 720p it does less scaling but wastes 40 lines. If I change to 1080i the TV will downscale to 768i right? which while gaining the 40 lines of resolution will cause an interlaced output which isn't ideal for games. So either way I'm screwed. I'd love an explanation.

[segages]

I wondered this too. I think it's something to do with the HDTV standard having to be able to accept 1024x768 (4:3) over VGA. Anyone feel free to correct me.

[sj33]

Cheaper to manufacture.

As a result though, you gain resolution for PC use and 1080 downscale

[EJG1980]

Makes you wonder why the HDTV standards body (or whoever it is that decides these things) didn't think "It's cheaper to make 768p panels... let's make the standard HDTV resolution 768p!"

[Pirotic]

If I set it in the PS3/Xbox dash to 1080i then instead (atm it's 720p), will the TV itself scale it down to 768i or 768p? if its the latter I'd be dumb not to, but i'm not sure if it's possible to downscale an interlaced picture into a progressive one or not.

[charlesr]

Or why they didn't think "let's just make 1080p the standard and sod everything else" so that it is actually a standard....

[sj33]

If I set it in the PS3/Xbox dash to 1080i then instead (atm it's 720p), will the TV itself scale it down to 768i or 768p? if its the latter I'd be dumb not to, but i'm not sure if it's possible to downscale an interlaced picture into a progressive one or not.

LCD's are progressive, period. Any interlaced input needs to be deinterlaced. How good that turns out depends on how well the TV does it.
That's one of the reasons 480i looks really bad on cheaper LCD's, but comparable to 480p on higher end ones (?700+).

1080i will downscale to 768p.
On my Bravia S, 1080i looks lovely on my screen, you can't tell the input is interlaced.
My old LG just rendered 1080i as 540p, so the results were ****.

[Pirotic]

I have a fairly recent Toshiba, I'll change my xbox360 and PS3 to 1080i then and gain that extra 40 lines of progressive resolution over 720p, cheers for the info!

I still think it's silly they market x768 LCD's as "720P HDREADY" when it transpires they look better running 1080i.

[sj33]

Well, all 360 games thus far are 720p, so your best leaving it at 720p unless you watch HD-DVD's regularly.

As for PS3, a lot of games are 1080i/p. We discuss this what to do with the PS3 here http://ntsc-uk.domino.org/showthread...4&page=1&pp=10

On paper, 720p>1080i for games, but if your TV can handle 1080i well, then there may be no real visible difference in the manner of refresh, so you may benefit from running 1080i games as I.
Go set your 360 to 1080i and try a few games out, see if you find it inferior to 720p or not.

The PS3 will apparently run 720p games as 720p, which is a good thing really.

No-one seems to agree on a definitive conclusion with the PS3 tbh, with some saying you should choose 720p for games always, others disagreeing as long as the TV handles 1080i properly. Having tried my Bravia S in 1080i and being impressed, I'll be using that on 1080 games on 360.

[Pirotic]

Okey doke, 720p for the xbox, 1080i for the PS3 (which will go down to 720p for 720p games anyway).

I really hope in the next couple of years 1080p becomes the only HD standard, will save future generations a whole lot of hassle,