If you are going to be using huge footage items, then it’s best to invest some time planning your work. With regards to image sizes, I recommend starting with something decently sized, no larger than 1Kx1K. Then scale it as required.
The idea here is to get a gauge on how big your footage should be.Once you’re done with the moves, you’ll need to look at the scale values for the layer to know how huge your ‘final’ footage should be. Navigate to the keyframe value with the largest percentage for scale. Right-click on the Scale value within the Switches Column in the timeline, and select Edit Value. In the accompanying popup window, change units from Pecentage to Pizels.
This value is what you will need as the maximum pixel size for the footage. you may want to pad the values for contingency. But working quickly in this manner allows you to ascertain your pixel (resolution) requirements without breaking AE’s image buffer.
Cheers
Roland Kahlenberg
https://www.broadcastGEMs.com – Adobe After Effects project files
https://www.myspace.com/rorkrgbspace