Question / Help 4:3 aspect ratio, but I like to have widescreen

[Robertino]

Hi everyone,
This may sound like a simple case but I can't seem to get it done.
As I choose my webcam as a video source OBS will display only a 4:3 picture, while -as far as I know-
I've put all my settings on widescreen.
On Xsplit broadcaster the wide picture gets seemlessly displayed.
What can this be?
Regards,
Robertino