An overhead projector enables you to present individual, static transparencies that contain business information and statistics. If you're accustomed to sharing movies, sound files and illustrated documents from your notebook computer through a digital projector, stepping back to older technology may prove challenging. In a pinch, an overhead projector can help you get your message across, but the technology shows its age and its limiting disadvantages.
Whether you print, copy or handwrite on individual sheets of transparency film to convey your message, you'll quickly discover that the cost of these plastic sheets adds up to more than pocket change. Although you can reuse them to make the same presentation to a different audience, transparencies eventually begin to show their age. Printed material can flake off, and the plastic itself can scratch and dull over time.
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Heat and Noise
An overhead projector uses a bright lamp to push its message from the illuminated transparency onto a mirror and then onto a projection screen. Like any incandescent bulb, the lamp generates byproduct heat while the device operates -- a significant enough amount of heat to require a noisy fan to dissipate it. You'll need to source lamps from an office-supply store or website, as they're not a garden-variety off-the-shelf item you can pick up where you buy regular light bulbs.
Bulky, Heavy Equipment
Picking up an overhead projector qualifies as weightlifting. With most of its bulk in the bottom of the projector, along with the lamp and fan, topped by a long neck with a mirror assembly on the end of it, it's difficult to carry for more than a short distance. Where they're moved from room to room, you'll often see them on wheeled carts that double as projection platforms.
Finding enough room for an overhead projector can be a challenge, especially in small rooms or facilities with hard-to-move furniture. In classroom-style setups in which these projectors see frequent use, one desk may become a permanent projection stand. If the equipment rolls in on a wheeled cart, you may be forced to move furniture to make room for it. Plan ahead by checking out the space in which you'll be presenting.
Unlike today's digital generation of projection hardware, overhead projectors only display what you place or write on their platforms, and only if you put your message on transparency film. That forces you to prepare your message in advance, or write it out longhand with a grease pencil. If you want to present audio or video with your slides, you'll need a separate player to add multimedia to your message.
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