What is the "best" video format to import into Aftereffects (for keylight plugin)

Question

Hello All,
I
have various choices in Adobe Premiere (CS4) for exporting.
The top choices seem to be
Microsoft AVI
Avi uncompressed (this i assume is much better than just Microsoft AVI -- for greencreen keylight work?)
And Quicktime.
So I assume my best choices would be Quicktime or AVI Uncompressed.
Any reason to choose Quicktime over AVI uncompressed?  Or visa versa?
Thanks
Rowby

Answer 1

The best starts with the camera and recording system. Any system that gives you 4:2:2 color at 10 bit as original at a high data rate is best. Well almost best. Best is 4:4:4 color at 32bit, but you must have a pile of cash to capture this way.
The worst modern acquisition formats are the mpeg systems used by phones and some digital still cameras. For cameras that independent film makers can afford, let's say under $10K, I'd say that the best, meaning highest color depth and least compression goes something like this. There may be some room for debate on the order of the  Panasonic and Sony P2/XDCAM but the new AVC-Intra format is, for now, at the top:
Panasonic AVC-Intra (the replacement for P2)
Sony XDCAM and HDCAM SR (new generation)
Panasonic P2 DVCPRO
HDV
DVC Pro 100 SD
DVC Pro 50 SD
AVCHD (though this is a HD format I've put it below sd formats because of compression)
DV
I've left off analogue formats because they require specialized capture cards. I also left off the Red and the Canon and Nikon still cameras that capture HD because the Red is too expensive for the list and the still cameras use a compression scheme that I haven't played with yet. I think that the Canon 5D Mark II may produce footage that will key quite well but don't know where to put it in the list.
Once you have the original footage you can either work with the native formats or transcode to your favorite lossless format. I prefer Animation Codec Quicktime because it is universally available to and simple to transfer between platforms. Also good are sequential tiff or even png formats. Many folks use jpg compressed Quicktimes. I don't know many pros that use avi's because uncompressed are so huge and the compressed avi's are pretty messy.
For the production pipeline to keep working you almost always have to stray from the native codecs because they do not support alpha channels. If you choose to work with P2 (MXF) files, which AE CS4 handles just fine, then you will have to render to a codec that supports alpha channels or render separate alpha channels to bring your footage into a NLE or Flash and with transparency preserved.
I hope that answers your question. You can't easily fix a poor quality original by simply transcoding to a lossless format.