Okay that's good to know. Every time I try to load a hdri file to ezdome it gives me an error message. I may need to redownload it.

I am not a fan of completely enclosed rooms hence my suggestion about a wall or ceiling made invisible/removed. I would be interested to see what solution is suggested that works.

Area lights perhaps?

Eta: I am fond of loading a hdri onto the background node using the material setup from ghostship2's tutorial, but OP uses Poser 11 and I use P12.