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Digital Video & Audio

pixel aspect ratios in After Effects CS4 and other applications in Creative Suite 4 Production Premium

I’m not saying anything new in this blog post. I just wanted to gather together in one place several useful resources on the subject of the new, corrected pixel aspect ratios (PARs) that were introduced with the CS4 versions of the applications in Creative Suite 4 Production Premium.

First of all, I’ll point out that these new PARs don’t affect high-definition work or work that is destined for computer monitors. This issue is strictly limited to the old standard-definition television formats.

Of course, the first place that I’d hope that you’d go is the “Pixel aspect ratio and frame aspect ratio” section of After Effects Help, which gives a terse explanation of the change and provides tables with the new PARs and the new square-pixel equivalents for when you’re creating square-pixel assets to work within compositions with non-square pixels.

Mike Afford has put together a good explanation on his website. Mike used to work for the BBC, but to get a direct statement from the BBC, you should check out their own paper about the underlying technical details.

Chris Meyer provides a very detailed and thorough article on the ProVideo Coalition website that explains the history and reasoning behind the new and old pixel aspect ratios and—more important—how to work with these new numbers in any circumstance.

Chris also has a “New pixel aspect ratios” video on the Lynda.com website that covers some of the same material, but in video form and not in as much depth.

Chris also shows how change a preference setting to allow you to continue to work with the old PARs in CS4 with old projects.

UPDATE: See this post for the news that Final Cut Pro 7 uses the corrected pixel aspect ratios, too. And see this thread for information about the Foundry making the change as a bug fix in Nuke.

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