You can take japes' great "lower res textures" point a step farther by even using lower res geometry for things that will remain distant in the scene as well. You have to be careful about things that will approach camera eventually in an animation, obviously -- e.g., the Vicky Reduced Rez figures in the BG (or even posettes, or super low rez substitutes for extremely far distant people) and the full rez Vicky3 only as the foreground "hero" character(s). Also, is your render going to have fairly narrow Depth of Field? If only one plane of the images is going to be in clear focus, all objects closer or nearer than that plane which will be blurry anyway should get lower resolution textures and/or geometry -- why expensively render detail only to expensively blur it away later? - - - --