The shutters on the front three concaves (6 sections each rotor) are arranged such that 4 shutters of the outside of downhill rotor and 4 on the inside of the uphill rotor close with the same linkage/hydraulic cylinder.
In this vid covers are closed completely and then opened completely, can't show you 4D here, that would require actually running machine and be over 4 degrees lateral angle.
Each concave has 9 divisions so with 8 shutters even when completely closed the very bottom division is open.
The shutters that stay closed at the top of the frame are the manual covers control by a valve on the side of the combine, all 9 divisions close on those, the 4D shutters are either automatic or manual from the seat.
NFI how well it's going to function, I do know one of the fields to harvest this fall goes from 20 degrees one way to twenty degrees the opposite way in 100 meters of travel, Elnora rolling hills here 4D comes!
By the way, by making a 5 second video and then simply pausing it or scrolling to position beats our Photobucket extortion friends!