I'm trying to do a logo for work, and have used 3d, lighting, a camera, and cc Light Burst 2.5. I'm not sure which of those is causing this, but the lighting is creating a kind of divided gradient from light to dark. Instead of a smooth transition, there are jagged divisions between lighter and darker areas. I'm am exporting in Apple Prores 422 at 29.97fps and at 720p. Here's a link to what I'm talking about: http://www.youtube.com/watch?v=siiL0_GIEag
Note: I JUST uploaded the video so it may have to process for a while before you can see it. The problem also may not be noticeable until the video processes fully to 720p resolution.
Nothing to see there but conventional banding. There is no way to completely avoid it when working with lower bit depths and compressing to 8bit CoDecs. Simple computer math - if the area to be covered is wider than the possible number of unique color levels (1024 for 8bit), the same color is assigned two two or more rows of pixels, resulting in the gradient looking broken. ProRes is 10bit, though, so working in 16bpc in AE and saving to that should perfectly avoid all the issues. Also consider using a different design. Full frame gradients are always problematic. you will be back to the same problem latest when you need to do a DVD or provide it as Flash video for the web for instance.
Try using an Adjustment Layer with Grain or Noise - that should also damp down the banding.
Gochya. Thanks for the info!