If you're using the slideshow templates in PD, the only way to control the background is as I posted above: (a) modify CameraView or 3D template or (b) place "background" image first in Scrapbook, Montage or Collage slideshow.
There are manual (very manual) ways to do it, but I'm not sure that's what you're after.
Cheers - Tony
Visit PDtoots. PowerDirector Tutorials, tips, free resources & more. Subscribe!
Full linked Tutorial Catalog PDtoots happily supports fellow PowerDirector users!