Help with capturing fullscreen

[WhoDatMilkshake]

Hello! I have been recording for a while, but I don't know how to stretch the screen to the point where there are no black bars left, but also to the point where it won't fit on the screen, like this:

Any help is much loved!

 

[FerretBomb]

Normally this happens when you are running a 16:10 resolution, but your canvas is set to 16:9.
The only real fixes for this are to set your canvas to a resolution with the correct aspect ratio, or to crop your video source vertically.