When I render a photorealistic animation the file takes 25 hours, gets corrupt and does not produce a video.  What setting should I use to make this 35 second clip and make it photorealistic?  Right now I get an opaque white moving file that jumps around for a second and then tells me its corrupt and closes.  The render appears to be taking place but no usable outcome video is made.  There is however a 4.5 gig video file created, it just is way not what I am looking for and doesn't play beyond 1 second.