Alright, so here's he low down on animations. The time it takes to render an animation, and the resulting file size of the animation are both due to the same factors. You can adjust the following settings for your animations by clicking on the Options tab in the Animation Export Dialog Window.

- Resolution (Pixel Dimensions):The Higher the resolution, the longer it takes to render, and the higher the file size will be. In most cases we render our final animations in HD (1280 x 720) at 16:9 aspect ratio. But we'll render previews at 640 x 310 to make sure that everything is looking good before we take the time to let the hi-res version render.

- Frame Rate: The higher the Frame Rate, the longer it takes and the bigger the file size will be. we render our final animations at 24 Frames Per Second (FPS). Previews are rendered at 10, or 12 FPS.

- Video Encoder: There are much better encoding options on a MAC than on PC - so we render almost everything on MAC. For the Highest Quality stuff (and massive file sizes) we render using TIFF Uncompressed. For high quality stuff w/ med file sizes we render using Apple Animation encoder. For high quality stuff with much smaller file sizes, we render using H.264 encoder.

- Encoding Quality: Most all of the encoders have options to adjust the quality of the encoding process. Final animations are rendered at the highest level of quality and drafts are rendered at med quality.

The difference between a final render and a draft render using the setting above - drafts render in a matter of minutes, and the files are small enough to send in an email. The final ones will take up to 10 hours to render a 2 min animation, and the file size could be up to 100Mb. 

In addition to the stuff above, you'll also notice that the animations will take significantly longer if you have a model with lots of detail in the model (thinks like 3D Cars, Trees, etc.). if shadows are turned on, or you have any edge styles applied to the model, that will increase rending time too. 

hopefully that helps. let us know if you have any other questions. 

-mike