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Pixel Aspect Ratio
First off I’m sorry for this repetive question I know I’ve seen similar posted, but none answered my specific question. I shoot on my friends HD camera in 1080 and capture it and bring it into after effects, the actual pixel sizes are 1440×1080. I realize this means it has a PAR of 1.33. But when I click on the “correct pixel aspect” button on the comp window to work with it and off again to render into a quicktime animation file and play in quicktime, the video is squashed because I take it quicktime does not recognize the correct PAR. So my question is what is the best way to correct this. What I’ve been doing is importing the 1440×1080 footage that is interperted as having a 1.33 PAR and placing it into a full 1920×1080 comp with a PAR of 1. That’s been working for me. Am I loosing any quality in doing this and is there a better way? Thank you for any help.
Greg Robbins
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3 Replies
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The video is just for fun for me and my friends. Its a shot of a army tank I modeled and then matchmoved the original footage in pf track and composited the tank and footage together. So the footage is only going to be used for showing it to friends via playing it in quicktime (ie why I needed it to look correct in quicktime) and uploading it to vimeo, youtube. The footage was shot on a HD panasonic I forgot the name (hvx100 I think sounds familiar)but it records to a P2 card.
Thanks for responding dave I appericate all the advice you give everyone. This is a very helpful forum -
Yea that’s what I usually do compress with adobe media encoder. Thanks for the help. I just wasn’t sure if using different PAR’s would loose quality. Thatnk you for lending your knowledge once again Dave!
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Having worked with footage of this nature for some time, from cameras like the HVX 200 that record a smaller number of actual pixels than are displayed (using a scaling algorithm), I think I can state with some confidence that you will indeed be losing a small amount of quality this way because you are stretching the footage horizontally from its actual pixel resolution to force it into its “correct” aspect ratio.
Better I’ve found to leave it native and squished in AE, using Pixel Aspect Correction on for reference, but toggling it off to check edges when pulling keys, etc.
This keeps your graphics and effects, as well as the footage itself, at their sharpest throughout the project. If you are finishing in an editing app, as is usually the case, then you can render at this native size and pixel aspect ratio, and the editing app will know how to properly interpret and display the clip. From there, you can output everything as you usually do.
If you’re going straight to the web, you could drop your comp into that square pixel comp just before rendering, in case the compression app can’t interpret the native-to-displayed resolution correctly. (I’m assuming you plan to compress for the web in another app, as compression is not one of AE’s strong suits.)
I wouldn’t mind hearing another opinion on this workflow, though. I do believe it’s essential for pulling the highest quality keys with footage of this nature, but for non-keyed footage the difference in quality might be visually imperceptible.
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