I'm compositing on a show (which involves live action bgs and actors mixed in post with CG characters,) that's having some problems with aspect ratio. A scene will be
shot 16x9 hi def progressive scan on a Sony HD 900. The shot is then brought into Maya 3 for reference for lighting and animating the CG actors. The compositing of the
CG into the live action scene is done in After Effects 4.1, and then edited and finished in an AVID DS3.0. Our problem is this. We have not established whether or not wht(if any) is the calculation to ensure the same pixel aspect ratio is maintained throughout the process. We
have been having to stretch and distort CG elements to make them proportional to the live action BGs. I'm wondering if a) the definition for, say, D1/DV NTSC Widescreen
in Adobe After Effects is the same in all the software in the pipeline(SONY HD 900, MAYA 3,AE4.1, AVID DS 3.0) is there a standard formula one can use to ensure
pixel aspect is maintained? Thanks in advance for your help, Jon
I'm not familiar with HD-CAM at all, as I have never used it (we use DV-CAM for video), but there are a few thngs I can assume, and you should investigate further for whether or not they are true or relevant. If anyone can correct anything that I'm saying, please do, as so not to give anyone any false information - and so I'll know.
That said, the ratios and standards should all be compatible; i.e. D1 in Maya should be D1 in After Effects, or anywhere else. I'm not sure whether you ar having a problem with screen aspect ratio or pixel aspect ratio, but I believe that HD pixels are 1:1 (square), and obviously the screen is 16:9, and I am assuming your shots are at full res (1920x1080). You may have only meant it as an example, but just in case, D1/DV NTSC is not compatible with HD, so you can't use that standard to bring in your shots if they are shot with HD...After Effects has an HDTV frame size option, so when you create your comp, use that setting. Also make sure that you are rendering out the right sizes in Maya (HD 1080 in the resolution presets), and obviously you should be bringing in the same sizes in the Avid|DS.
is there a standard formula one can use to ensure