Projector screen gain explained
What screen gain really does to brightness, with a computed table. Most ambient-light-rejecting screens sit below 1.0 — darker than plain white.
Gain is how much light a screen reflects back compared with a reference matte-white surface, which is defined as 1.0. A 1.5-gain screen sends about 50% more light toward the centre seat; a 0.6-gain screen sends 40% less. The counterintuitive part: **most ambient-light-rejecting screens have gain below 1.0**. Across the 24 ALR and CLR screens we track, 15 of them — 63% — are darker than plain white. CLR screens for ultra-short-throw projectors sit around 0.6. They buy contrast by rejecting light from the sides and ceiling, and they pay for it in brightness, so they need a brighter projector, not a dimmer one.
Gain is a trade, not a free upgrade. A high-gain screen is more directional: it concentrates light toward seats on the centre axis, and viewers off to the side see a dimmer, sometimes uneven image — the effect called hotspotting. A low-gain screen spreads light evenly and holds black levels better in a room with lamps or windows, which is exactly what ALR and CLR materials are engineered for. That is why the premium screen in a bright living room is usually the darker one. Size the projector for the screen you actually chose: multiply its lumens by the gain before comparing against what the room needs.
What gain does to on-screen brightness
| Gain | vs plain white | 3 000 lm on 100″ | Typical of |
|---|---|---|---|
| 0.5 | -50% | 545 lx | CLR screens for UST |
| 0.6 | -40% | 655 lx | CLR screens for UST |
| 0.8 | -20% | 870 lx | Darker ALR |
| 1.0 | — | 1090 lx | Plain white / matte |
| 1.2 | +20% | 1305 lx | Typical ALR |
| 1.5 | +50% | 1630 lx | High-gain, centre seats only |
Frequently asked questions
Updated