Hi Wulfi, I'not realy sure what you mean, but one of the odd ( but sometimes very useful) things in LW is that 100% transparent objects are still "seen" by the renderengine. So a solution might be to use 100% object dissolve rather then transparency or just "unseen by rays" in the object item properties. hope that is what you were asking for, if not maybe post a pic here that I can see the problem. Ciao Thomas (He who is lightyears away from beeing a guru)