> Why doesn't AE let me create 1440 x 1080 comp with 16:9 aspect ratio?
It is. Your screenshot shows that you're looking at a 16:9 composition.
Look at the "Frame Aspect Ratio" value on the right side of the dialog box in your screenshot. It says that your composition frame is 16:9.
You need to read up on that pixel aspect ratio stuff...
There is a pixel aspect ratio compensation switch at the bottom of the comp window. It looks like a double-headed arrow. Toggle it on, and you will see 16x9.
Yes, this's how I thought at the beginning.
Frame Aspect Ratio is showed as 16:9 but my comp is not displayed as a wide screen.
Instead, it's a 4:3 comp.
Thanks Dave, that button will strench my comp to 16:9 ratio.
I did a small test by rending my comp. the movie file is still giving me 16:9 ratio.
Do you know why I need to toggle this?
As I expect I make my comp work after choosing the right settings, the case here doesn't.
You have created a composition that uses non-square pixels. This is correct for a composition with the number of pixels that you have for a frame aspect ratio of 16:9. Clicking the button that Dave mentioned shows you the result in the Composition panel with non-square pixels.
You need to read the documentation about pixel aspect ratio, as Mylenium suggested:
You are not understanding pixel aspect ratios and your footage. Here's the problem, 1440 X 1080 is a standard comp size for a non square pixel format. There's only one of those formats and it's not useful for anything but acquiring footage from the cameras that use that format. You're better off, unless you specifically need to render back to the DVCPro codec that supports this frame size, working in a 1920 X 1080 Square Pixel HD comp. Your graphics will look better, you won't be sub pixel sampling still images brought in to the project, and you'll be able to see exactly what the project will look like.
If you drag your DVCPro HD footage into a 1920 X 1080 comp then it will fit perfectly. No need to do anything.
If there's a specific reason that you MUST render back to the DVCHD Pro format then let us know. Other wise, just use a standard HD comp with a matching frame rate. You will be a happier camper
Thanks for the URL.
yes, you're right. don't quite understand the aspect ratio. read some stuff on the internet, found out something. still need to be familiar with the uses.
yes, if i create a 1920 x 1080 comp and drag my video footage there. everything works.