Hi Larry-L. Ok, I don't have poser 5, only 4, so I don't know how much of what follows is correct for Poser 5. Light coming through a real window will bounce off the walls adding a difused light to the room, in Poser you need to componsate for this missing reflected light in some way. "It would be a nice feature of P5 to be able to place an infinate light withiin a scene so you could control the lighting effects:" Normally Poser(4) uses two types of lights Infinite and Spot. Internally, in the library files, Infinite are "type 0" and Spot are "type 1", there is a third, undocumented type of light "type 2", these seem to a hybrid of infinite and spot, they share the same type of shadow cams as spots, but the "rays" seem to be parallel, and they can be positioned in a room like spots. Perhaps this is the kind of thing you are looking for. There are two ways to convert a light to "type 2", you can either edit a Poser library file (lt2, cr2, etc) directly in a text editor, or use a pose (pz2) file on the lights from within a Poser document. The syntax for a pz2 to convert a light of "type 1" (Spot) and species "spotLight" to a "type 2" is:

{
version
    {
    number 
    }

light spotLight 1
        {
        lightType 2
        }
}

Where "light spotLight 1" is the internal name of the light. There are pose files to convert between the diffrent light types included in my "SpotLight Utility Pose Pack 1" in the free stuff.