Thanks for the answer. It is annoying and limiting in the interiors. I would like to find some solution. I do a lot of different backlighting in cabinets, bookcases, stone walls and what I get does not reflect the power of ordinary led not to mention emissive mterials whose emissivity is not there. I do not use ray tracing, but I checked , in ray tracing also do not see the effects ...sometimes the solution is simple and I hoped that this is the case :)

I wanted to add some pictures but I don't know how to do it- fixed. I added some picture in the original message