Ok, I assume your looking for a light through the window effect? Is the room (inside) being lit at all? If you’re looking for a halo effect (light beams) that requires a setting on the lamp itself to produce. Photon lights won’t provide help with the window. Also, just to be sure is the window area an open area or does it have ‘glass’ over it. If it has glass you may have an issue. Last I tried it casts ashadow and blocks GI (Yafray GI.)
As described in my first mail, I will first try to switch off
this “digital” effekt of haveing either a complete black
window or a complete white window. I cannot see anything
a had set for the world material through the window.
To describe my setup of the scene again
(from my inital mail):
I built a room (with two surfaces – a “real” rom…no simple cube) and adjuste the normal vectors. Then I cut a “whole” into the room: A window.
I put a area light and an emitter plane behind it in the room together with a cam.