Motion pixel aspect ratio weirdness

[Geoffrey Cox]

Hi,

Can anyone explain this?

Sent a clip (HDV 1440x1920, pixel aspect 1.33) from FCP6 to Motion 3 to do some slow motion work. Made sure the media settings in Motion matched this. But, the image is noticeably laterally stretched; something's wrong.

To cut a long story short, after numerous failed fiddlings I tried something counter-intuitive by changing the pixel aspect ratio in Motion to 1:1. Hey presto it worked - the image is now displayed (and more importantly, processed) correctly. But I thought the whole point about 1440x1920 was that the pixels are rectangular and so the image size is still 1920x1080? Maybe Motion 3 doesn't recognise this?

So i solved the problem but it worries me that a) I might be setting up problems that will rear their head later and / or b) I have a fundamental misunderstanding of something...