Fran, if you do a search on the net there are a fair number of HRDIs out there to play with. Although I don't have Bryce 6, we over in the Imagine forum tho not having true HDRI capabilities have a user who wrote a script that uses the light gen plugin to freate arrays of light based on the image that very closely approximates HDRI renders so I obviously went out and found bunches of em. Sorry now I didn't save the links but I got em with Google so you can too.. ...

 

Once in a while I look around,
I see a sound
and try to write it down
Sometimes they come out very soft
Tinkling light sound
The Sun comes up again