A small question, have you managed to get the letterbox display in the camera movements?

I searched the forum and only found that the setting 1 should work , zero would not display any letterbox, and more than 1 could give problems...but whatever value I use it doesn´t seem work.
I´m sure I´ve played some community maps that had it (actually one had the letterbox the whole level, can´t remember the name) . Maybe I´m doing something wrong, or it doesn´t work with the last update or wthatever. Any tips?
Thanks in advance.

Cheers!