As the competition heats up on the show floor, many companies are turning to large-screen projection systems to get their message out to attendees. Big-screen presentations can boost your booth’s visibility, traffic and memorability. But choosing and using these systems is no simple matter. Here’s an example: an exhibit manager was planning an in-booth software demonstration using large-screen projection. When it came time to rent the projection equipment, he specified a video projector. Unfortunately, he didn’t realize that because the demonstration was computer-driven, he needed a special type of projector. Computer graphics require a higher horizontal scan frequency (which affects image resolution) than video. When the projector arrived at the booth, the exhibit manager discovered his error. His only recourse was to rent an expensive scan converter, which also reduced the image quality. If the exhibitor had been specific about the application in the beginning, he could have avoided the added cost and headaches.

Here’s an overview of the basics to help you understand your options and large-screen projection. The benefit of projection is that it can provide seamless images. This is especially important for product demonstrations. To be effective, front projection needs a darkened theater because images wash out when exposed to ambient light. With rear projection, light is thrown upon a translucent screen from behind. The images are less affected by ambient light, so images are brighter. However, the best viewing angle for this format is directly in front of the screen. Images viewed from the sides tend to fade. Unless you plan to build an enclosed theater, rear projection may be your best option for in-booth presentations.

With a free-standing system, the projector and screen are separate, which means that the distance from the projector to the screen may be varied. The advantage of free-standing systems is that they can support larger screen sizes than a self-enclosed system. In a self-enclosed system the distance from the projector to the screen is fixed and screen size is limited to diagonal measurements of from 40 inches to 72 inches.
The trade show environment presents many challenges for projection systems. Before you begin your search for the right projection system, there are several questions you need to ask yourself. The answers to these questions will help determine which type of projector is appropriate for your needs.

1. What will you be using for input? Three common sources are videotape, computer or laser disc. The type of input you use will affect the type of projector you need. For example, computers require a projector with a higher horizontal scan frequency than videotape and laser disc. The type of projector you specify must be able to accommodate the scan frequency requirements of the input source.

2. How large will the audience be? How far away will they be from the screen? The size of the audience and their proximity to the screen affects the size of screen needed. The larger the screen, the more powerful the projector must be. Keep in mind that viewers should be no more than 40 degrees off the screen’s perpendicular axis. Generally, the first row of your audience should be no closer than twice the screen’s height; and the distance of the last row should be no more than eight times the screen’s height.

3. How much space do you have? Free-standing projection units typically require more physical space in the booth than self-enclosed units. Also, consider the screen size you choose in relation to your booth size.

Choosing the right projection system is not for the amateur – use an audio/video specialist. His time and talent is money well spent – remember a picture is worth a thousand words