I tried few things and search the webs - with no results. Here is the simple scene:
and link to the file, if anyone want's to check it: simple scene
In the scene I have a flat mirror plane, sphere over it and 3 emitter objects working as lamps. As you can see on the picture, at this angle we can see reflection of one of the "lamps" in the mirror plane. What I would like to achieve is keep the reflections of this lamp on the sphere surface, but make them invisible on the plane underneath. I can't just block glossy rays in emitter object's panel - that will turn off the white highlights on the sphere too. I can't render sphere and plane separately, cause I need those highlits visible on the sphere's reflection in the plane too! Looks like such effect is impossible atm in blender, as what it would require would be some kind of setting that allows to turn off and on reflections from other objects selectively on material or the object itself. But maybe someone knows the answer and I'm just too bad in blender to know the answer. Please, if You do, help me :)
PS: This is just a sample file to show the problem. So let's say we have to keep the camera angle and positions of all objects - so we can't just rotate the camera to find the angle that hides those big reflections from the frame.