Halloween projection mapping from your phone

Put a few pumpkins, a foam tombstone or a skull on a table, aim the projector at them and darken the room. Add a shape over each prop, drag its corners until it hugs the outline, and give each one its own jack-o'-lantern or ghost scene.

Hang a white sheet, shower curtain or sheer white fabric tight across the inside of the window and project onto it from the room. People outside see ghosts and glowing eyes through the fabric while the room behind stays hidden.

Map a shape to the window so the scene stays inside the frame, and keep the room dark: any light behind the fabric washes out the image.

Set the projector on a tripod in the yard and aim it at the garage door or a light-coloured wall. Map one shape to the door and fill it with fog, a giant face or slow-moving ghosts: slow scenes read better from across the street than fast ones.

Outdoors needs a much brighter projector than a window. The small one we use indoors looks faint on a garage door; our outdoor pick is the XGIMI Horizon 20 Pro.

Map every window, door and wall panel as its own shape and give each a different scene, so the house itself seems to come alive instead of wearing a rectangle of video.

Set up the projector across the yard or the street, draw a shape over each surface on your phone and drag the corners until they line up. Most house fronts take under 30 minutes.

This is the job that needs the brightest projector. The XGIMI Horizon 20 Pro fills up to about 6.6 metres (300 inches) of width from around 8 metres back, enough for a garage and the windows around it. For a wider, brick or two-storey front, map the section people see from the street.