I've been making animations in after effects for a few years, but things are getting bigger and bigger. I make 2,5D 'worlds' with PSD's (smart objects). But preview rendering takes forever even on Quarter resolution.
The system is fast enough with multiple SSD harddrives. And the right settings.
I've been searching online what is the best file format to use.
Will it get lighter/faster to render with JPEG's or PNG's? I cannot pre render pre composed layers because I need to be able to make changes all the time.
I hope someone can tell me more about this subject.
There really isn't an optimal size or resolution that "fits all". It depends on what you're doing with each still. Is it the "hero" of the comp, so that you're zooming in on it, and showcasing it larger than full screen? Is it lit such that you can get away with some loss of resolution because it's a background piece, or in the shadows? Does a still only appear as about 1/8 of the full screen size? What is your final output resolution?
Here's a pretty good encapsulation of all of the issues: