Well yes and no, go into the sky lab, and first off, use a BLACK background, it's a preset. then turn off the sun in the same control area. Also, turn off fog/haze, which I'm pretty sure is off by default in that black preset. If you don't use these settings you'll get some pretty weird looking renders (bryce doesn't like anything but the black sky for renders like these ( I have no idea why )) The booleaned sphere reduces the amount of noise in reflective/transparent mats in the scene for some reason. It has to do with bryce's inherent back faced culling or whatever it's called. But basically, you want it on the positive side of the polygons.