Understanding Projector Brightness (Lumens)
Lumens measure how much light a projector puts out. It's an important number, but on its own it can't tell you whether a projector will work on your stage. Three things decide how bright you need to be.
1. Image size
A projector's light spreads across the whole picture. Make the image twice as wide (and twice as tall) and the same light covers four times the area, so it looks a quarter as bright.
2. The surface
A purpose-made screen reflects light efficiently. Painted flats, a cyc, a scrim or textured scenery usually reflect less, and darker or colored surfaces less again.
3. Light on the surface
This is the big one in theatre. Front wash, side light, spill and house lights that land on the projection surface wash out the image. Keeping light off the surface (with angles and shuttering) often helps more than a brighter projector, so talk with your lighting designer early.
Starting points
Many school auditoriums and mid-size theatres are well served by a projector in the 7,000 to 10,000 lumen range with the right lens. Larger venues, full-stage images and brightly lit productions often call for 13,000 lumens and up. These are starting points, not rules or guarantees.
Other factors
- Some lenses reduce maximum brightness on certain projectors.
- Eco or extended modes extend laser life but lower output.
- Dark scenery is less demanding than bright skies and white backgrounds.
Want a recommendation for your room? Send us your image width, surface and lighting through the Projector Finder. Full guide: How many lumens does a theatre projector need?