When render, objects are black even with light

Hello,

I am new to render so I have much to learn.

I have a problem and I can not find the solution on the internet. When I set the view in rendered it looks good. But when
i do a final render everything is black. I have set some planes as emmision ( a light). So i dont know the problem. But i think it is something with the settings.

Thanks for the help !

Greetings,
Dominique

PS. I have a print screen so you can see what i mean.


I all redy solve my problem !