Selecting the Right Projector: Brightness
The brightness of a projector is measured in lumens. A wax candle generates 13 lumens; a 100 watt bulb generates 1,200. This means higher lumen projectors produce more vivid images for the same size image. When you increase the image size, you spread the same lumens over a larger space, reducing the effective brightness of the image.
Most people not familiar with lumen measurements find it difficult to determine the minimum brightness they require for their presentation. A variety of industry sources recommend these guidelines:
- Projections below 700 lumens usually require dimmed lights. (Watch out! Dimming lights often leads to a sleeping audience.)
- Projections between 700 and 1200 lumens are adequate for most boardroom and conference room settings with normal lighting.
- Projections of at least 1000 lumens are necessary for shaded daytime presenting outdoors.
- Projections over 1500 lumens are recommended for courtroom settings.
- Projections to larger audiences (hundreds of people) or in broad daylight should be about 2000 lumens.
- Projections larger than 300" diagonal often require over 2200 lumens.
- Projections to concert or amphitheatre audiences (thousands of people) need between 3000 and 10,000 lumens.
Projectors over 1000 lumens perform handsomely for the majority of business presentations. They deliver impressive images to small audiences, and can produce large images with little light control. If projecting to hundreds or thousands of people, however, you may want something brighter.