Shrinking file sizes

[Fitz]

I've made a few animations in M3D but one major problem I keep having is the file size of any finished video. They end up absolutely massive given their duration and are effectively unplayable on anything other than a serious desktop computer. As an example, a four minute zoom video I made ended up being 5.5GB which I take to mean that I'm doing something obviously wrong. Virtualdub is what I've been using which outputs the video as a .avi file, and a compression codec called Xvid MPEG-4 since all the other ones that came with the program produced garbage results. Presumably there's some balance of quality settings where things still look acceptable while not resulting in massive file sizes, but whenever I adjust the quality setting in the video codec everything quickly turns to mush before I can reduce it to something reasonable.

When rendering I've been outputting the images as PNG files at 1920x1080, with each frame ending up at ~4.2MB which is probably part of the problem. M3D has the option to reduce the quality of the output images and I've always had it set to 100, is it necessary to lower this setting as well while doing the actual rendering?

I'm somewhat clueless about the whole process and undoubtedly doing various things wrong, but would like to actually optimize what I'm doing at this point where possible.