Poser renders everything in the scene, regardsless of it's visible or not. I'm not 100% sure it also renders things that are placed BEHIND the camera I remeber Stewer (I think) posting about it once. So it CAN speed up your renders if you for instance make the bodyparts that are covered by clothing invisible.

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You just can't put the words "Poserites" and "happy" in the same sentence - didn't you know that? LaurieA
  Using Poser since 2002. Currently at Version 11.1 - Win 10.