Free Sample
The Complete Handbook of Projectors
For professionals, businesses, and serious hobbyists who need to understand, select, install, and operate projection technology
by Alumigogo Books
Chapter 1: Understanding Projectors
A projector is an optical and electronic device that takes an image—from a computer, camera, video player, or other source—and magnifies it onto a screen or other surface for viewing by a group rather than an individual. Unlike a television or monitor, which is designed for viewing by a few people at close range, a projector's job is to throw an image across a room or hall large enough for dozens or hundreds of people to see simultaneously. This difference in purpose and scale shapes everything about how projectors work, how you choose them, how you install them, and how you maintain them.
Projectors are not exotic technology. They've been in continuous use since the 1880s in the form of magic lanterns and film projectors. What has changed is the underlying light source and the way the image is formed and manipulated. Modern projectors use one of several established technologies—DLP (Digital Light Processing), LCD (Liquid Crystal Display), LCoS (Liquid Crystal on Silicon), or increasingly, laser or LED light sources—all of which accomplish the same fundamental task: take light, modulate it to encode an image, and focus that light onto a distant surface.
To understand why projectors are designed the way they are, it helps to think about what they're actually doing differently from other display devices. A television or computer monitor has a fixed viewing distance—you sit roughly 6 to 10 feet from it—and a fixed screen size. A projector is designed to handle vastly different