How to Set Up a Halloween Window Projector: Screen, Distance and Videos

A ghost drifting past your front window looks like a lot of work. It isn't. The whole effect comes from a small projector inside the house, a translucent screen hung behind the glass and a video made for windows. This guide walks through the setup in order: the screen, the distance, the picture, the room, the videos and a few safety basics.

What you need

• A projector. Any small video projector works; a tilting stand and keystone correction make aiming much easier.
• Something to catch the picture: rear-projection film or fabric, or a thin white sheet. Clear glass on its own won't show anything.
• Window-display videos on a USB drive, your phone or a streaming device.
• A tape measure, a table or shelf for the projector, and a power strip if the outlet is across the room.

Step 1: Hang the screen inside the window

Hang the screen on the room side of the glass and pull it as flat as you can. Wrinkles and folds show from the street. A rear-projection film or fabric gives the most even picture; a thin white flat sheet is the low-cost option and works well for silhouettes and simple scenes. Our rear-projection screen vs. sheet guide compares the options and covers mounting without damaging the window.

Pick a window without grilles if you can. Window grids and the rail across the middle of a double-hung window sit between the screen and the street, so they show up as dark lines across the picture.

Step 2: Work out the distance and picture size

How big the picture gets depends on how far the projector sits from the screen and on its throw ratio. Our projector has a 1.37:1 throw ratio, which means the picture is about 1 ft wide for every 1.37 ft of distance. Here's what that works out to for a 16:9 picture:

Figures are approximate. For other projectors, divide the distance by the throw ratio in the manual to get the picture width; the height of a 16:9 picture is a little over half the width.

To size it to your window, measure the glass you want to fill, then set the projector back until the picture just covers it. A smaller picture is also a brighter picture, because the same light lands on a smaller area, so don't go bigger than the window needs.

Tall windows

Most windows are taller than they are wide, while a projector's picture is wide. Many window-display videos come in a vertical version that puts the figure in a tall strip in the middle of the frame with black on both sides. Black areas send out very little light, so on a window they mostly disappear and you see the figure. For a tall window, set the distance so the picture's height fits the glass and let the black sides fall on the wall or frame.

Step 3: Aim and square up the picture

Put the projector on a table, shelf or stand behind the window. The closer it sits to the middle height of the screen, the less correction the picture needs. If the window is high, tilt the projector up. Our projector sits on a 180° rotating stand for this, and auto keystone squares up the picture when it's aimed at an angle. Focus it with the room dark so you can see the fine detail.

Keep the projector's line of sight clear of curtains, plants and blinds, and make sure nothing stands between the lens and the screen once people start moving around the room.

Step 4: Understand rear projection and mirroring

With the projector inside, you're doing rear projection: the projector lights the back of the screen, and the people outside look at the front. That means they see the picture mirrored left to right, the same way writing on a sheet of paper looks backwards when you hold it up to a lamp.

• For ghosts, skeletons, falling snow and other scenes without text, mirroring rarely matters.
• For scenes with words, numbers or a character who points a certain way, use the video's rear-projection version. Many window-display packs include one, already flipped so it reads correctly from outside.
• Some projectors have a rear or flip setting in their projection menu. If yours doesn't, use the rear-projection version of the video instead.

Check the result from the sidewalk, not from inside the room. From inside you're looking at the back of the screen.

Step 5: Make the room dark

Window displays work after dark. A small projector like ours (120 ANSI lumens) is made for dark rooms and after sunset, and every projector looks better the darker the room is.

• Turn off the lights in the room with the window, and close doors to lit rooms behind it.
• Turn off any porch or yard light that shines on that window from outside; light falling on the screen washes out the picture.
• Start the display at dusk and check it from the street once it's fully dark.

Step 6: Play and loop your videos

You can play window videos three ways:

• From a USB drive. Copy the video files to a USB drive, plug it into the projector and open them in its media player. This is the most reliable way to run a display all evening.
• From your phone. Mirror your phone over Wi-Fi and play the video there. It works, but your phone is tied up for the night and notifications can pop up on the window.
• From an HDMI device. A laptop or a streaming stick plugged into the HDMI port can play videos or streaming apps. App availability on our projector's built-in system can vary, so for streaming apps we suggest an HDMI streaming stick.

Set the player to repeat (loop) so the scene keeps going. If you have several short clips, put them in one folder and repeat the whole folder, or join them into one longer file on your computer. If you use an outlet timer to cut power at bedtime, don't expect the video to restart by itself the next evening unless your projector's manual says it has an auto-play feature.

Where to get window-display videos

Our projector doesn't come with any Halloween or holiday videos, and it has no built-in scenes, so you'll need to add your own. Good sources:

• Digital decoration makers. Several companies sell downloadable or USB packs made for windows, often with vertical and rear-projection versions. AtmosFX is one of the best-known names.
• Independent creators on online marketplaces who sell window-projection loops of ghosts, pumpkins, snow and similar scenes.
• Your own footage. Film family members in costume or a shadow puppet against a black background; on a window screen, the black disappears and only the figure shows.

Stick to videos sold or made for home display, or footage you made yourself. Avoid clips copied from films and shows, and characters from movies or TV that you don't have rights to use.

Power and safety

• Keep the projector indoors. Ours isn't weatherproof and runs from a wall outlet. The window display works precisely because the projector stays inside behind the glass.
• Watch for condensation. Cold glass can collect moisture; keep the projector and its power adapter back from wet glass and sills.
• Leave the vents clear. Don't wrap the projector in a curtain or push it against the screen.
• Route cords safely. Run them along the wall, away from walkways, and use a power strip rather than a chain of extension cords.
• Switch off at bedtime rather than leaving the display running all night.

Quick troubleshooting

From our store

Mini Smart Projector for Halloween & Holiday Windows

Native 720p, 120 ANSI lumens, a 180° stand with auto keystone, Android 11, Wi-Fi, Bluetooth and HDMI. Window screen and videos sold separately. Free shipping and 30-day returns from Depoodeal.

View product