Although both widescreen, there are differences in PAR. Just crop off, and this is from memory, some pixels from the top and bottom. I don't remember the exact number, but they have been posted here repeatedly. Just look around. Ann Bens has given these crop factors in many replies. Something like 12 from the top and 8 from the bottom or there abouts.
Why is this?
Before the age of digital video, it was decided by technocrats that what we see in the end product (called the Clean Aperture) would be different from what was there in the original (called the Production Aperture). They left off some pixels at the side when they made the calculation for the widescreen Pixel Aspect Ratio. That process has unfortunately carried over onto digital video, and we're still using that same old analog PAR, instead of what we should be using when you calculate it for the entire frame. This results in the black bars you see.
In CS6, this is easily overcome by selecting Scale to Fill in the Export settings.
OK, thanks both.
So I presume, Jim, from your answer that the PAL DVD MPEG2 preset PAR is correct, and when I scale to fill the resultant exported MPEG2s will have the right proportions.
This being the case, I wonder at the necessity of Anne Ben's method?
I presume...that the PAL DVD MPEG2 preset PAR is correct
Nope. Adobe only uses the older, incorrect analog PAR for SD widescreen content. (This is justified by the fact that most everyone else also uses the wrong PAR, including the BBC, so at least things are consistent.)
Anne's method achieves the same end result. But with Scale to Fill, it's automatic.
No, when I wrote "I presume...that the PAL DVD MPEG2 preset PAR is correct" I meant that I presume it's correct enough for a circle to remain a circle throughout this process.
Have to say nothing has done my head in quite like this PAL issue. When Adobe changed their PAL PAR in CS4 and they published their raison d'etre for it I tried to understand... but since I was frameserving from the timeline to Procoder rather than using AME to do the DVD conversion it didn't really matter, as the DVD conversion was just fine using that method. Now that I'm trying to use AME and wean myself off Procoder this issue has raised its ugly head again.
Thanks for your help.
I meant that I presume it's correct enough for a circle to remain a circle throughout this process.
Not so sure that's correct either. Theoretically, you'd need to use the correct PAR for something round in the original footage to remain exactly round in the export.
Though I suspect that any distortion is negligible enough to go largely unnoticed.