Craig Birkmaier wrote: ... > For ANY given raster, the images will be sharper from > a progressive scan camera versus an interlaced camera. > Where we get into trouble is trying to equate different > formats with similar pixel clocks, such as 720@60P > versus 1080@60i. > > Clearly, the 1080 line format has more spatial > resolution along each line, but the vertical resolution > is subjective. ... the general consensus is that an > interlace factor of 0.60 should be applied, bringing > down the 1080 to 648, which is below the vertical > resolution of 720P, but above 540, ... Tom Barry: > I think with proper deinterlacing maybe you could get > slightly better than .6. I've seen .65 and .7 mentioned in the past, on many occasions. But one thing that seems to get lost in this is that even a 720p signal has to be filtered down some. I think Mark Schubin has mentioned a factor of .9 or so, to avoid aliasing. If we go around comparing properly filtered interlaced displays to unfiltered progressive scan images, we would only be talking with non-nyquist filtered computer graphics people. Not the TV audience. So in fact, even using the existing 1080i line standard rather than going to Tom's suggested 1440 X 1280i, the comparions is between an achieved: 1080 * .65 equals 702 vertical lines, and 720 * .9 equals 648 vertical lines of resolution. Whether today's displays can make use of the full 1920 horizontal pixels of 1080i is perhaps a matter of debate, but certainly more than the 1280 available with the 720p standard are usable already, in the best displays. If there's so much controversy as to what format provides the best images, it's probably because the competition is tight. The interesting part of this is that even without CRTs in the picture any longer, the competition might continue to be tight, for 1080 at 60i vs 720 at 60p. Bert ---------------------------------------------------------------------- You can UNSUBSCRIBE from the OpenDTV list in two ways: - Using the UNSUBSCRIBE command in your user configuration settings at FreeLists.org - By sending a message to: opendtv-request@xxxxxxxxxxxxx with the word unsubscribe in the subject line.