At about 31 minutes into the film, there are several shots of the "Black Pirate" aiming two swivel cannons at the viewer, interspersed with reaction shots of other actors. The first shot shows him in front of a whitish background (eg an overcast sky), the second such shot (a few seconds later) has a pitch black background. All such shots after that have the white background.
When the men following the Black Pirate are swimming up to the boat at the climax, shadows are clearly visible on a wall when they are shot at an angled view.