Altered State

The image behaves as though perception itself has come loose. Edges breathe, colour separates into its channels, focus drifts without anyone touching it.

The shot takes the audience inside a head. Rather than being told a character is impaired, they get a picture that behaves the way the character's seeing does.

Keep the subject readable, as the note says. The distortion has to be a layer over something the audience can still follow, or it stops reading as perception and becomes abstraction.

Small continuous movement beats large intermittent movement. A surface that swells and settles by a few percent, a focus that drifts and half returns, a colour fringe that comes and goes. Real perceptual distortion is restless rather than violent.

Colour separation is the cheapest strong cue. Pulling the red and blue channels a few pixels apart gives an edge fringe that the eye reads as wrongness before it identifies what it is.

Use it for intoxication, illness, panic, exhaustion, and any moment where the audience should distrust what they are being shown.

Skip it when the scene has to be believed as a record. Once the image is unreliable, everything in it becomes a question.

A distortion bends the architecture of the space, so the room is wrong and the way of seeing is fine. An altered state leaves the space alone and makes the seeing wrong, so edges, colour and focus misbehave in a room that is still a normal room.

The test is where the fault lies. Curved walls is a distortion. A straight wall that breathes and fringes is an altered state.

Fear and Loathing in Las Vegas (1998) keeps its rooms recognisable while the surfaces move, the carpet patterns crawl and the colour comes apart, so the audience reads the impairment as belonging to the character rather than to the building.

Total abstraction comes back and the subject is gone. Say the subject stays readable and the distortion sits over the top of them.

The second failure is one big warp that holds still. Ask for continuous small movement: edges breathing, focus drifting, colour separating and coming back.