I have a 50 minute video (600x600) that I need to render out of AE CS3. If I render uncompressed it's about 90gb. If I try to compress it, the best I've been able to get is 1.6gb. Is there anyway I can get it better without losing much quality?
If you can tell us what codecs you're using, it would be very helpful. Without knowing what you're using, it sounds as if you're on the right track to efficient compression, by first outputting an uncompressed master - the next step is to output your delivery formats, and you should be using Adobe Media Encoder for that, since it offers better, higher quality compression.
We also need to know what it's being delivered for (playback devices).