ALR Screens: Ambient Light Rejection for Real Rooms

If your projector looks washed out with lights on, the problem usually isn’t lumens—it’s the room. An ALR screen (ambient light rejection screen) improves perceived contrast by directing projector light to viewers while rejecting light from lamps and windows. This guide explains how an ALR screen works, which type to buy for UST or short-throw, and how to avoid artifacts. For gaming setups, see Best Gaming Projectors (https://aixprojector.com/guide-best-gaming-projectors/) and UST Gaming (https://aixprojector.com/best-ust-gaming-projectors/).

What is an ALR screen?

An ALR screen uses a directional surface and often a gray base layer to reflect light from the projector toward viewers while absorbing or deflecting ambient light. The result is deeper blacks and richer color in bright rooms. ALR is not just “brighter”—it’s smarter light control.

Not the same as white matte. White screens scatter light in all directions, so room light washes the image.
Not just gray paint. A gray ALR screen adds directional optics; plain gray paint lowers overall brightness without effective rejection.
Great with UST. Pair a UST-ALR (also called CLR) with ultra-short-throw projectors in living rooms. See UST vs Short-Throw (https://aixprojector.com/guide-ust-vs-short-throw/).

How ALR screens work (the optics)

ALR surfaces use micro-structures to create directional gain:

Lenticular/CLR (for UST): Sawtooth “ridges” accept light from below (the UST path) and reject overhead/side light.
Fresnel (for long-throw): Concentric rings direct light from the projector’s axis back to the audience; strong rejection of off-axis light.
Hybrid gray ALR: Diffusive gray layers with mild directionality; less aggressive but wider viewing.

In simple terms: an ALR screen increases useful light to the viewer and reduces stray light to the screen—so contrast looks better even at the same ANSI lumens.

Types & compatibility (UST-ALR/CLR vs long-throw ALR)

Choosing the wrong ALR screen for your projector angle can make the image worse.

UST-ALR / CLR (Ultra-Short-Throw)

Engineered to accept light from below (UST path).
Blocks overhead and front light (ceiling lamps, windows).
Typical gain 0.6–1.0; very directional; viewing cone ~100–140°.
Do not use with ceiling-mounted long-throw—image will look dim.

Long-Throw ALR (Fresnel or lenticular for standard throw)

Designed for front or ceiling-mounted projectors.
Blocks side and ceiling light; sometimes narrower viewing cone.
Typical gain 1.1–1.3 (spec varies); may hotspot if placed poorly.

Gray “ALR-like” screens

Matte gray increases black floor in modest light; rejection is limited.
Good budget step-up from a white wall, but not a substitute for true ALR screen optics.

Need help choosing by room? See Best Short-Throw Gaming Projectors (https://aixprojector.com/best-short-throw-gaming-projectors/) and the Best 4K Projectors hub (https://aixprojector.com/guide-best-4k-projectors/).

Gain, viewing cone & room light

The three dials you must balance on an ALR screen are gain, viewing cone, and ambient light level.

What “gain” means

Gain is brightness vs a reference white screen at the center.
Higher gain = brighter on-axis, but narrower viewing cone and more hotspot risk.
Lower gain (e.g., 0.6–0.8) = wider viewing, better uniformity, deeper blacks, but less peak brightness.

Typical targets by room light (rough guidance)

Dark theater (0–30 lux): Matte white or low-gain gray (0.8–1.0). ALR optional; contrast is room-driven.
Dim mixed room (30–80 lux): Gray ALR screen ~0.8–1.0; keep lights off near the screen plane.
Living room (80–200 lux): UST-ALR for UST; long-throw ALR 1.1–1.3 for standard throw; control ceiling spots.
Bright showcase (200+ lux): Aggressive ALR, narrow cone, meticulous light control, or consider a TV.

Viewing cone tips

Place seating within the screen’s half-gain angle.
Avoid mounting the projector too far off-axis; follow the screen maker’s chart.
If family seats are very wide, choose a lower-gain ALR screen to keep uniformity.

Learn more about screen basics and viewing geometry in your Projector Reviews hub (https://aixprojector.com/projector-reviews/).

Artifacts: hotspot, sparkle, moiré, color shift

All ALR surfaces involve trade-offs. Here’s how to avoid common pitfalls:

Hotspotting: A bright “hot center.” More likely with high-gain Fresnel or off-spec throw distances. Fix with correct throw/height and moderate gain.
Sparkle/shine: Grainy glitter on bright scenes. Choose smoother UST-ALR materials; avoid aggressive metallic layers for 4K close-up viewing.
Moiré with 4K/pixel-shifting: Pattern interference between panel pixel pitch and screen micro-structure. Minimize keystone; align carefully; choose screens tested for 4K/UHD.
Color shift/off-axis desaturation: Strongly directional ALR screen materials can drift in color at angles. Use wider viewing cone if seats are wide.
Laser speckle (RGB laser): Fine “sparkle” on some tri-laser projectors; lower speckle by slight defocus (~1–2%), different brightness modes, or a less glossy screen.

Sizing, mounting & maintenance

Size & aspect

Common sizes: 100–120″ for UST living rooms; theaters may go larger.
Aspect ratio: 16:9 for games/streaming; 2.35:1/2.39:1 scope screens for movie-first rooms.
Check manufacturer throw calculators; do not rely on keystone to “force fit.”

Mounting the ALR screen

Orientation matters. UST-ALR has an arrow or “UP” mark; upside-down mounting ruins rejection.
Flatness & tension. Fixed-frame or rigid panels keep micro-structures aligned.
Lighting discipline. Kill downlights near the screen plane; move lamps to the sides behind viewers.

Cleaning & care

Micro-structured ALR screen surfaces scratch easily.
Use a soft microfiber cloth; avoid alcohol or harsh cleaners.
Follow the vendor’s cleaning instructions; blot, don’t rub.

Buying tips (checklist)

Match the type to the throw. UST needs UST-ALR/CLR; long-throw uses Fresnel/lenticular ALR.
Pick gain for your seats. Wider seating = lower gain; single sofa = you can go higher.
Control nearby light first. A modest lamp at the screen plane can undo any ALR screen.
Avoid keystone. Use lens shift/placement; geometry processing can add artifacts and input lag. See Projector Input Lag, Tested & Explained (https://aixprojector.com/guide-projector-input-lag-explained/).
4K close-up? Choose a smooth, 4K-rated ALR screen to reduce sparkle and moiré.
UST in bright rooms. Always pair with UST-ALR; gray paint or generic ALR won’t reject from the right direction.
Plan audio and cable paths. Keep power and HDMI runs tidy; avoid light fixtures directly in front of the screen.

Setups & recommendations (by scenario)

Family living room with a UST

Screen: 100–120″ UST-ALR/CLR (gain 0.6–0.8).
Notes: Block ceiling spots near the screen; dim side lamps. For gaming targets see UST Gaming (https://aixprojector.com/best-ust-gaming-projectors/).

Small room / shared apartment (short-throw)

Screen: Gray ALR screen or moderate-gain long-throw ALR with wide viewing cone.
Notes: Keep projector behind players; avoid keystone. Compare options in Best Short-Throw Gaming Projectors (https://aixprojector.com/best-short-throw-gaming-projectors/).

Light-controlled theater

Screen: Low-gain gray or matte white; ALR optional.
Notes: You’ll get maximum native contrast from the projector. For image quality, see Best 4K Projectors (https://aixprojector.com/guide-best-4k-projectors/).

Mixed office / presentation space

Screen: Fresnel ALR 1.1–1.3 gain.
Notes: Prioritize legibility, uniformity, and seating angle. Add task lighting behind the audience.

Where this guide fits in your site

Gaming flow: Best Gaming Projectors hub → Input Lag Explained (https://aixprojector.com/guide-projector-input-lag-explained/) → UST/Short-Throw spokes.
Cinema flow: Best 4K Projectors (https://aixprojector.com/guide-best-4k-projectors/) → this ALR screen guide → Projector Reviews hub (https://aixprojector.com/projector-reviews/).

FAQ (paste these into your FAQ plugin to output Schema)

What is an ALR screen?
A directional screen that reflects projector light toward viewers and rejects ambient light, improving perceived contrast in bright rooms.

UST-ALR vs standard ALR—what’s the difference?
UST-ALR (CLR) accepts light from below for UST placement and blocks overhead/side light. Standard ALR is tuned for front/ceiling-mounted projectors.

Does an ALR screen make the image brighter?
It doesn’t add lumens; it increases usable light to viewers and reduces stray light, so blacks look deeper and colors pop.

Can I use a UST-ALR with a ceiling-mounted projector?
No. Directionality is wrong; the image will look dim or uneven.

Which gain should I choose?
Wide seating and 4K close-up viewing favor 0.6–1.0. Narrow seating or presentation use can go 1.1–1.3, at the cost of viewing angle and higher hotspot risk.

Will an ALR screen fix everything in daylight?
No screen beats direct sun. Use blinds, relocate lamps, and avoid downlights near the screen.

Does an ALR screen affect input lag?
No. Screens are passive; lag comes from processing. See Projector Input Lag, Tested & Explained for fixes.

How do I clean an ALR screen?
Use a soft microfiber cloth and gentle strokes. Avoid alcohol, abrasives, or hard rubbing.

ALR Screens Explained (2025) | Choose the Right UST/Short-Throw