1080p or 720p video format for a PAL DVD project?

[Alister Chapman]

Not entirely, they are only referring to 1080i v 720P and are not considering the use of 720P50(60).

The downconversion from 1080 to 720 in the EX is very good and must incorporate anti-aliasing as the aliasing in the 720P images is minimal. When downconverting either 1080 or 720P to SD you must include further anti-aliasing and this is where you enter a grey area. If you are dealing with 1080i it is very difficult to accurately anti-alias as you are working with fields where on a line by line basis there may be temporal differences and if you try to anti-alias just a single field, then you are working with in effect an image where half the data has been discarded, this in itself can lead to bad aliasing. Now it is possible to get good quality downconverts from 1080i, BUT you need a very good conversion process and you need to take a lot of care. 1080P is much easier to deal with as you don’t have the field issues, but your maximum temporal resolution (movement) is either 25fps or 30fps and for sports or fast action this may not be appropriate.
The compromise therefore is to shoot 720P50(60). Most of the required antialiasing required to get from the 1080 resolution of the imagers will have already been done in camera. There are no issues with field aliasing or field order errors and you have a temporal resolution of 50/60 fps. Even a downconversion with only poor anti-aliasing will look acceptable and you are likely to get more consistent results.

So while in theory 1080 should give a better image and with great care and the right software can do this. The reality is that 720P at 25/30fps or 50/60fps depending on the temporal motion you want is much easier to deal with and the difference in the final SD image between one acquired at 1080 and 720 is going to be so small that I very much doubt that anyone would ever see it.

Alister Chapman
http://www.xdcam-user.com

[John Winski]

Thank you! 720p50 it is! Crew just arrived in Cambodia–thanks so much for your help!