I'm working on a commercial with full-HD (1920x1080) resolution. I just got the product-shot for the end of the spot that was made two years ago in standard definition (PAL 720x576 anamorphic). Now I'm wondering about one thing: what happens when I upscale my SD-material for the HD-sequence and then downscale it again when I finally render out my HD-sequence in SD or put my HD-Comp in a SD-Comp for rendering? Will there be an unnecessary quality loss or is After Effects smart enough to see that the original part was SD once? Is there a way to keep the full quality when upscaling/downscaling?
I think what I want to achieve is normal in Shake or Nuke, but I'm not shure if After Effects works the same way.