Projector Basics

Introduction to Projection Technology

While the most common projectors today are digital projectors for use in business presentations and home theaters, the modern digital projector is just the latest of many projection display devices. We’re all familiar with movie theater projectors, but there are also models for other film formats, including 16mm and 8mm film projectors. Slide projectors had their moment in the spotlight too, but their use has continued to decline since the advent of digital photography and computerized slide shows (and Kodak’s decision to stop making them).

Film and slide projectors are considered transparency projectors, much like the traditional overhead projectors that remained the dominant presentation tool for many years. As the term “transparency” suggests, these projectors produce an image by shining light through a transparent medium (the film, slide or overhead transparency) and projecting that image onto a screen.

With technology continually leaping ahead, it’s no surprise that digital data, video and overhead projection systems have been replacing old-fashioned transparency projectors in the marketplace and in homes, schools and offices. Old fashioned CRT (cathode ray tube) technology isn’t extinct yet, thanks in part to its long, successful track record in traditional televisions and computer monitors. But most multimedia and video projectors today use digital technology - mainly LCD (liquid crystal display) or DLP (digital light processing)technology - to produce their images.

Digital image production is not the same as a digital signal, and only newer projector models come with DVI (digital visual interface), which is a technology allowing digital machines to communicate and to receive digital video or data signals from computers and DVD players. Composite video, S-video and VGA are some of the more familiar analog signal types, although component video has also been an option for several years, providing better image quality by separating different parts of the signal.

The quality of your image depends on several factors, including the resolution of your projector, its brightness and the aspect ratio of your image, but these aren’t the only specs that will influence your decision. Take the time to familiarize yourself with common projection features and terminology so you can make an informed purchase. You many also want to get to know what projector parts and accessories you’re likely to need. Don’t forget to take advantage of Guide 2 Projectors’ tips for projector installation, maintenance and repair to help you get the most out of your investment.