It seems that Point light in Poser 13 are having an issue and could not be used in superfly. The setup Rhia474 would be trying to do would end up wrong as Light in a object as the " Dist End " can't be set ! It seems having no effect when changing the distances and acts like a Infinite Light in superfly. Either it is a error in Poser or Point lights are not supposed to be working in superfly. In Firefly they work as they should.

If using this Point light system in a gem like you plan it would light up the whole environment when rendering with superfly. Someone might check the Point lights Dist End to confirm that issue, else it is just on my side and ignore my comment.