HDR/EXR skies work great in Daz as bhoins has outlined and when added to your dome don't have the same limitations as the image backgrounds(Photos). You can also rotate the dome to place the sun/sunset right where you want it. If you google either 360°HDR Skies or CG Skies you should be able to get hold of some freebies for the hobbyist/non commercial use. Unless you have a image you really need to use I recommend you take a peek.

- Johnny G

"Try animation to get things moving"

lpr001@renderosity.com