Halloween hologram projection: how to make floating ghosts with a projector

Halloween hologram projection is the effect where a ghost seems to hang in mid-air in your doorway, garden or window, with nothing around it. It isn't a real hologram. It's a projector, a see-through material and a video with a black background, and the illusion works because in the dark your eye only sees the light. In the clip beside this article, two glowing skeletons dance on black, the kind of footage that makes a hologram work, fitted to two panels from an iPhone with EasyMapper Studio.

Here's how the effect works, what products like Goblin Glass and shadow projectors actually do, and how to build your own.

Three things create the illusion:

• A see-through surface. A fine black or grey mesh (often sold as "hologram mesh" or "scrim"), sheer white fabric, or a screen behind a window. It catches the projected light but is almost invisible in the dark.
• A video on black. Black means no light, so only the ghost lands on the mesh. Nothing outlines the edges of the screen.
• Darkness behind it. The space behind the mesh has to be dark so the figure looks like it's floating rather than painted on a sheet.

It's a cousin of the old stage trick called Pepper's ghost, which uses angled glass to reflect a hidden figure. Modern Halloween versions skip the glass and project straight onto mesh.

These are the products that come up when people search for Halloween holograms, and they work in different ways:

• Goblin Glass is a small USB-powered novelty projector that shines a still scary face, from a swappable film slide, onto a window or wall. It's simple and plug-and-play, but it shows a fixed image rather than a moving video, and it isn't a hologram.
• Shadow projectors are small spotlights that cast a silhouette, such as a witch or a shadow figure, onto a wall. They're cheap and simple but only do one effect.
• Hologram mesh kits are a roll of scrim plus a set of videos to play from your own projector. This is the most flexible option and the one you can build yourself.

If you already own a projector and an iPhone, the mesh route costs the least and lets you change the ghost every night.

1. Hang the mesh. Stretch hologram mesh or sheer fabric across a doorway, a porch opening or between two posts in the garden. Keep it tight and away from lights.
2. Place the projector. Put it in front of the mesh, out of sight if you can, aimed square-on. Connect your iPhone over HDMI or AirPlay (connection guide).
3. Map and play. Add a layer in EasyMapper Studio, drag its corners onto the edges of the mesh, and drop a black-background ghost video onto it.

The mapping step matters more for holograms than for anything else. A projector's beam is bigger than the mesh, and any light that misses it hits the wall or the house behind, which ruins the floating effect. When the layer is fitted to the mesh, the light stops at its edge.

Anything with a pure black background and a single bright figure:

• Ghosts that drift slowly across and fade out.
• Skeletons that dance or walk.
• Floating heads or eyes, which look especially strange in mid-air.
• Jack-o'-lanterns that seem to hover in the dark.

EasyMapper Studio includes Halloween loops and live effects such as Ghost Swarm, all drawn on black. The Halloween projector videos guide covers where to find more.

• In the front doorway. Hang mesh in the open door so trick-or-treaters see a ghost waiting inside.
• Across the porch. Between two porch posts, the ghost appears to stand on the porch.
• In a window. Mesh or a sheer curtain behind the glass gives a ghost inside the house. The Halloween window projector guide covers this setup.
• In the garden. Between two trees or stakes, with a dark background, a figure seems to stand on the lawn.

Is it a real hologram?

No. Real holograms are 3D images made with lasers. Halloween "holograms" are 2D projections on a see-through material. In the dark the effect is convincing, especially from a few metres away.

How bright does the projector need to be?

For a doorway-sized mesh a few metres away, 1,000 to 2,000 lumens is comfortable after dark. Mesh lets some light through, so a bit more brightness helps. The lumens guide has the details.

Can I use a white sheet instead of mesh?

Yes, but the edges of the sheet will show. Mesh disappears in the dark; a sheet looks like a screen.

Do I need a laptop?

No. EasyMapper Studio maps and plays from an iPhone or iPad. It's free to download, and Premium ($7.99 a month or $39.99 a year, with a trial) unlocks the full feature set.

Hang some mesh, play a ghost on black and open EasyMapper Studio. Your doorway will have a visitor before the trick-or-treaters do.