FILM

Shafting the screen: the projector beam maintains its angle as it meets the screen and keeps on going, introducing volume as well as light, just as Paris, Cairo and Venice of a century ago happen to pass. Passing through the tunnel mid-film, a red flash will signal you to switch your single Pulfrich filter before your right you to before your left (keep both eyes open). Centre seating is best: depth deepens viewing further from the screen. Handle filter by edges to preserve clarity. Either side of filter may face screen. Filter can be held at any angle, there’s no ‘up’ or ‘down’ side. Also, two filters before an eye does not work better than one, and a filter in front of each only negates the effects. (Ken Jacobs)