xpdev, for good interior scene renders in poser with no sunlight, do what bill and the others mentioned.  use d3d's renderFF script to set IDL IC = 100, IDL samples to 4096 or higher, IDL intensity to <=1.0, and IDL bounces to 16 or 32.

use light-emitting objects that are as large as possible and which have bevelled/curved edges, make sure no other surfaces have diffuse >=1.0, turn off tone mapping in render settings, decrease bucket size to 32, increase pixel samples to 16, use shading rate <=0.2.  do not attempt to use poser render settings screen to set IDL quality/bounces.  use d3df's renderFF script instead.