is there a way to ram preview a comp.....make a minor adjustment and then only have to render what was revised, so that you retain the rest of the ram preview of the unchanged area?
The entire frame must be rendered so if you changes involve the entire layer then the layer must be rendered. However, with CS6 and CS, if you make a change that only effects frame 20 thru frame 50 then only that part must be re-rendered. This functionality is better in CC than in CS6. Before CS6 all frames must be re-rendered for a preview.