Dutch Roll

The frame starts level and goes off level while the audience watches. Because the tilt arrives during the shot, it reads as something going wrong in the moment rather than as a style applied to it.

A fixed cant announces itself at the cut and then stops being noticed. A roll that keeps going never settles, which is why it works for a character losing their footing.

The camera rolls on the lens axis during the take, usually slowly and usually without stopping. Five or ten degrees is often enough, and past about thirty the shot stops reading as unease and starts reading as a stunt.

Direction carries a little meaning on its own, though the effect is mostly in the fact of the movement. What matters more is that the move is continuous and never resolves.

A strong horizontal in frame is what makes it visible. A horizon, a doorway, a tabletop. Without one, a rolling frame can go unnoticed.

Use it as a scene turns, on a drug or a fever, and when a character realises they have been lied to.

Do not use it everywhere. The effect depends on the level frames around it, and a film that is always canted has nothing left to cant.

A dutch angle is fixed. The shot starts canted, stays canted and the audience adjusts within a second. A dutch roll moves into the cant while they watch, and they never adjust.

Camera Roll is the full rotation and is usually about geometry or weightlessness. Dutch Roll stops part way and is about mood.

The model delivers a fixed canted frame, because a dutch angle is far more common in its training. Say the horizon tips during the shot and starts level.

The other failure is a roll so large it reads as spectacle. Ask for a slow partial roll and give it a limit, such as leaning steadily off level without turning over.