Projector brightness is measured in ANSI lumens. ANSI stands for "American National Standards Institute", who created a scale by which to measure the overall brightness value for projectors. The measurement represents the average value of 9 points on the projected screen image. The higher the ANSIv lumens value the brighter and sharper the projected image will be. \r\nWith a measurement of less than 1000 lumens, viewing can be hard unless in a darkened room. With a measurement of more than 3000 lumens, and it may be possible to see even in a sunlight filled room. There are several additional variables to consider as well as lumens, such as lamp bulb type, LCD technology and contrast ratios. If any of these variables is adjusted, it will make two projectors with the same lumens measurement display images of different quality. For example, a projector with a halogen lamp will appear darker than a projector with a metal-halide bulb.