Can I use a plain wall instead of a projector screen?

Yes, you can project onto a plain wall, and plenty of people do. Whether it looks good enough comes down to three things: how much light is in the room, how smooth and neutral the wall is, and how much picture quality you expect. This guide covers what a screen actually does, how to get the best out of a wall, and when a screen is worth buying.

What a projector screen does that a wall does not

A screen is a surface made to be projected on. It is flat, evenly coloured and reflects light in a controlled way, so the picture is evenly bright from edge to edge. A wall is made to be painted, not projected on, and its flaws show once light is thrown across it.

• Flatness and texture. Roller and orange-peel textures catch the light at an angle and put tiny shadows in the picture, which softens fine detail and text. Dents, joins and cracks show up as lines or patches.
• Colour. A cream, grey or tinted wall pulls the whole picture that way. A screen surface is neutral, so whites stay white.
• Even brightness. Gloss and satin paint can bounce a bright patch of light straight back at you (a hotspot). Screens are designed to spread the light evenly.
• Contrast in a lit room. Light from the room lands on the picture and washes out dark scenes. Ambient light rejecting (ALR) screens are made to favour the projector’s light over light from the room. A wall cannot do that.

When a plain wall is fine

A wall is a reasonable choice when most of these are true:

• You watch in a dark or dimmed room, such as a movie night in a lounge room or basement.
• The projector is bright for the size of the picture you want (see the lumens guide below).
• The use is casual: games, sport, kids’ movies or a temporary set-up.
• The wall is smooth, flat, matte and a light, neutral colour.

How to get the best from a wall

1. Choose the wall. Pick the flattest, plainest wall you have, away from windows. Avoid walls with texture, strong colour or things fixed to them.
2. Check the finish. Matte (flat) paint is best. Gloss, semi-gloss and satin paint reflect a hotspot of light back at you.
3. Keep it neutral. White or a very light neutral grey is best. If the wall has a colour cast, the projector’s colour settings can compensate, but expect to lose some accuracy.
4. Repaint if you can. For a permanent set-up, a smooth coat of flat white or light grey over a well-prepared wall is a clear improvement. Specialist projector paints are also sold. Results vary, so test a small area before you spend money on a whole wall.
5. Control the light. Close curtains, switch off lights that shine on the wall, and use dark furnishings near the picture so light does not bounce back onto it.
6. Frame the picture. A plain dark border around the picture, such as black tape or a matte black painted edge, makes the picture look sharper and the blacks look deeper.
7. Set the projector up properly. Place it square to the wall where you can, and use lens shift in preference to digital keystone correction, which reduces sharpness. Measure the picture size you can fill before you commit.

How bright does the projector need to be?

The brighter the room, the brighter the projector must be, and the smaller the picture it can fill well. As a starting point, 1,500 to 2,000 ANSI lumens suits a properly dark room, a room with some light needs 3,000 or more, and a bright room is better served by a bright projector and an ALR screen. Compare ANSI lumens between models. Other brightness figures on a spec sheet are often not comparable.

When a screen is worth it

• The room is never fully dark, such as an office, a meeting room or a living area with big windows.
• You want the sharpest picture, especially for text, spreadsheets and presentations.
• You are using a short-throw or ultra-short-throw projector, which normally needs an ALR screen made for it.
• The wall is textured, coloured or cannot be made flat.
• You want a permanent, tidy installation that looks the same every day.

Screens come as fixed frames (the flattest and most permanent), motorised or manual roll-down screens that retract out of sight, and portable pull-up or tripod screens. Match the screen’s size and aspect ratio to your projector and room: 16:9 suits most video, and 16:10 suits many computers.

A quick way to decide

Try the wall first. Project onto it for an evening with the lights off. If the picture is bright and sharp enough and the colours look right to you, you do not need a screen. If you find yourself squinting at washed-out blacks and uneven patches, a screen is often a bigger improvement than a more expensive projector.

Teracom Solutions supplies projectors and projector screens for homes, offices and venues. If you are not sure which suits your room, contact us with the room size, the lighting and the projector you have, and we will point you to the right option.