Been doing some experiienting with that myself. The probelght is useful if you want to use another node rather than the ambient to create light - so I guess plugging it into the ambient channel is kinda gilding the lily. I'm currently running a third test render on my machine - I've done one with the probelight node in ambient, one with it in alt. diffuse, and a third with purely ambient, no probelight. I'll post the results in a moment. jonthecelt