Setting up a window projection that actually lands on the glass

Why it is projected from inside

A window projection is a rear projection: the projector sits indoors, throwing onto a translucent surface in the window, and the image is seen from outside. That is the setup for a reason. The projector is dry, warm and not stolen; there is no cord running out of the house; and nobody walks through the beam.

It also means the surface matters as much as the projector. Bare glass does not hold an image — it needs something translucent to catch it. A pale roller blind or a sheer curtain works; a proper rear-projection screen works better, and is why kits that include one are worth more than their projector specification alone suggests.

The placement figures that are actually published

Throw ratios are rarely stated in this category, so most placement advice is guesswork. One of the products we rank publishes a real figure, and it is the most useful sentence in the whole category.

The thing that ruins every projected display

Ambient light, and it is not close. A projector competes with every other light source falling on the surface, and the ones that beat it are almost always yours: a porch light beside the window, a lamp in the room behind the screen, a hall light through an open door.

• Switch off the porch light. A light immediately beside the window is the single most common cause of a washed-out projection.
• Kill the room behind the screen. Any lamp behind a translucent screen is lighting it from the wrong side.
• Close the door to the hall. Spill from the rest of the house arrives at the screen exactly like ambient light outdoors.
• Check the street light. If one falls directly on the window, move the display to a different window rather than buying a brighter projector.

The content is the product

A projector is a box that shows what you give it, and the thing you will actually notice on the fifth night is the library. This is why the Kringle Bros effects kit is bought by people who already own a projector: sixteen AtmosFX effects and a 48 by 72 inch screen, with no hardware to pay for twice, and a library that keeps growing after the hardware stops being new.

At the other end, the dual-season window projector publishes twelve pre-loaded movies across Halloween and Christmas, which is the sensible choice if the display is one window for two seasons and you would rather not store two boxes. The full ranking is on Halloween projectors.

The setup checklist

• Measure the window opening, and the clear floor depth behind it.
• Choose the surface: rear-projection screen, pale blind or sheer curtain.
• Set the projector square to the glass — an angle distorts the image.
• Raise it to the height of the image centre rather than tilting it.
• Switch off the porch light, the room lamp and the hall.
• Go outside and look. That is the only view that matters.
• Put it on the same timer as the rest of the display.

For a small home, this is the display that takes no outdoor space at all, which is why it leads Halloween on a small porch. And if you are still choosing between projection and a physical piece, that comparison is on projector or inflatable.