Axiom Home Page Forums General Discussion Technical Questions Which gives better picture...720p or 1080i?

Alan, I think my opinion is biased towards 1080i as I have a 1080P set where the video processor in the TV apparantly holds the alternating 540 lines at 60fps and displays them as 1080P @ 30fps.

All I know is if I set my STB or Panasonic upconverting DVD player to 720P it looks more jaggy than if I set it to 1080i. I think its because the processor has to do more converting. Does that sound like a correct assumption?

CT, one conclusion that can be drawn from what you describe is that your set does a better job of de-interlacing than the player does. When 1080i comes in, the set(instead of the player)has to de-interlace the i to p because the set is inherently progressive.

Just saw this old thread and wanted to make a few comments.

ABC, Fox and ESPN-HD all transmit 720p for HD shows. Most other content providers use 1080i. So if your favorite HD shows are on ABC, Fox or ESPN, I'm not sure a 1080 native display would make much difference.

In theory 1080i material would look better on a native 1080 display, at least for scenes not involving lots of motion.

However -- I think all current 1080i providers aren't transmitting full-bandwidth 1080x1920 at 30 fps, but a cut-rate version using 1080 x 1440. This is due to limitations in current HD camera equipment and inability of the distribution chain to handle compression at full bandwidth.

By contrast providers of 720p (1280x720 at 60 fps) can handle the full bandwidth of that format, since the data rate is lower.

Stored HD source material such as Blu-Ray are in 1080 resolution, so a native 1080 display would be optimal for that.

However for current equipment, over-the-air, satellite and cable HD providers are only transmitting 1080i frames using 1440 x 1080 resolution for 1.55 megapixels per image. At 30 images per second, that's a data rate of 46.6 megapixels/sec.

By contrast, 720p images are 1280 x 720 for 921k pixels per image. At 60 images per second, that's a data rate of 55.3 megapixels per second.

So current 1080i still images have more pixels, but the overall data rate is lower. Thus when considering movement (panning, zooming, object movement) the effective delivered resolution may be less for 1080i than 720p as currently implemented.

The full 1080i implementation is 1920 x 1080, for 2.07 megapixels per image, at a data rate of , 62.2 megapixels per second. However it's unclear when content providers will be able to transmit this -- possibly not for a long time.

Native 1080 displays used to be very expensive, but prices have come down a lot. If I were buying a new display I'd get a 1080 native display.

You've got 1080i confused with 1080P and it will be a long time before anyone will have the bandwidth to tranmit in 1080P. A 1080P native set will not necessarily produce 1080i any better as the lines of resoltion in 1080i are half as the i stands for interlaced so it is infact only showing 540 lines of resolution drawn twice on the screen. must go can't finish thought, kids screaming in background.....