Did you see pirates of the Caribbean and watch the credits? It takes about seven minutes for all the CG people to scroll across the screen because there are hundreds involved in live animation. I came into graphics from a drafting perspective. If there were buttons on the shirt of that person 200 yards away with his back turned then they had to be done in 3D and the threads too! Ive since learned to cheat. Use images instead of objects for anything that is far away. Don't include anything that isn't in the visible scene. Premium effects are great but if your final film is only 320x240 what are you really going to be able to see? Its hard to know exactly what the problem is without some more information about your image. There are tricks and fixes available for many problems.