Hello,
I have made a cartoon character and i try to render the scene without a plane as background but i want to have the color reflection from the background (plane) . So i can later use photoshop for a specific background. Is it possible to render whitout objects, but with reflection or shadows from that objects?
For Cycles you could go to the Object Properties for the plane and under Ray Visibility disable Camera. You’d also have to select Transparent under the Film section of Render Properties. For shadows you might have to add an additional Shadow Catcher object.
You can do the following in Cycles, not sure if you can do this in Eevee.
Full, all objects shown.
De-select ‘camera’ in the View->Ray Visablity for the sphere.
Select Shadow Catcher for the back plane.
)thanks a lot. So easy! 
Well now ya have to show us what your final render looks like 
Good luck
Also – if you use nodes, different channels of information are presented as outputs (in addition to “everything combined”), and I believe that reflections and shadows are among them.
