How to manage background/focus?

There's many nice screenshots where the background is completely black/white and the character is on focus, I've tried some settings with DOF but all I achieved was to make the background kinda blurry, still not as near as the ones I've seen, is it made with reshade only?

Here is some examples
www.flickr.com/photos/158210133@N02/37677521845/
www.flickr.com/photos/158210133@N02/41315156530/

ChromaKey or Emphasize can give you monochrome backgrounds. DOF and the correct bokeh settings can yield some pretty nice results as well but differently.

Edit: I did those two with Emphasize:

Oh so it was those two all the time, I've been trying to do this for so long lol, thank you very much!