I put together a video in Sony Vegas, which I rendered as an Uncompressed AVI. The AVI looks amazing in AE but when I render it to any format (I tried about 6 or 7) the final product is either huge (10 Gigs for 46 seconds) or extremely terrible quality. What can I do to get a good looking video? The primary format of the video is AVCHD 1080x1920-60i. May the problem be in Sony Vegas or is rendering to Uncompressed the best thing to do to unfinished work that will go through AE later?
The best thing you can do is to render uncompressed any footage that will go into post work in AE or any other app. The worst thing you can do is try to render a compressed delivery codec from AE. Open the AE composition in Adobe Media Encoder and render from there. Usually MPEG2 or H264 (keyframe every frame) will give you a good result.