The background image is usually a picture of your house that you use to define your lighting scene. Try to take the best shot you can looking directly your house. Stand way back and get the entire scene in a single picture — or stitch multiple pictures together. I would not recommend taking a panoramic picture as it tends to distort a lot toward the ends. You can try this, though, if you like.
Setting the Image
To set the background image, click on the picture icon in the preview editor toolbar (pictured above). This will bring up a standard Windows file selection dialog box. Most standard image formats are supported (JPG, GIF, PNG).
Most lighting displays happen at night. You can use the slider next to the image toolbar button to set the intensity of the image on the screen. This can be changed at any time.
Resizing the Image
See Resizing the Preview Image section.