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Think of a business projector and you probably picture a typical front-projection setup in a conference room, with the projector mounted on the ceiling, or perhaps sitting on a table or desk, projecting the image from a spot somewhere in front of the screen. There are other options, however. It’s well worth knowing about them, because the next time someone in your company asks for a recommendation for a projector-or for any kind of large display for that matter-you have the potential to be a hero, and steer them in a direction they didn’t even know existed.
Throwing an Image
Many customers think business projectors are basically commodity items. They’re wrong. There are plenty of significant differences from one projector to another. The most important for purposes of this discussion is their throw distance-the distance they need to be from a screen to project, or throw, an image of a given size.
1. Standard Throw
Broadly speaking, projectors can have a standard throw, short throw, or ultrashort throw. These are vague categories without clear lines between them, but it’s usually easy to put a given projector in the right category. By definition, a standard throw is what you’ll get from the overwhelming majority of projectors. They have to be relatively far back from the screen-about 12 to 13 feet, to give you an image that’s 2-meters wide (about 100-inches diagonally at the traditional 3-by-4 aspect ratio) at maximum zoom for the lens.
2. Short Throw
For any given size image, short-throw projectors can sit significantly closer to the screen than standard throw projectors. For a 2-meter wide image, the distance shrinks to roughly 3 to 6 feet. One obvious advantage for a short throw is in a small conference room, where setting up a standard throw projector would be impractical. The shorter throw distance can turn “impractical” into “easy.”
3. Ultrashort Throw
For an ultrashort-throw projector, the distance needed from the screen shrinks even more-to 2 feet or less for a 2-meter wide image. The lens system in at least one ultrashort-throw projector is limited to slightly smaller images than 2-meters across, but at a distance from the screen of just 3 inches. (Very few projectors fall in the gaps between these categories, so there’s little reason to quibble over the exact range for each.)
4. The Default Choice
Along with the issue of how far a projector needs to be from the screen, consider where it needs to be in relation to the screen. Front projection with a standard throw is pretty much the default choice. It’s easy to set up; it’s what most people are used to seeing; and it works well under most conditions. But in some situations, it can be a challenge to position the projector so there’s nothing between it and the screen to cast shadows.
Mind Your Shadows
Mind Your Shadows
You can usually avoid shadows in front projection by mounting the projector on a ceiling, using a laser pointer to point to the screen (instead of trying to point with some physical object, like your arm, getting between the projector and the screen), or both. In a small conference room, however, positioning a standard throw projector to avoid shadows may mean putting it relatively close to the screen and living with a smaller image than you’d like. Choosing a short throw projector can usually solve that problem. If it doesn’t for a given room, an ultrashort-throw projector should certainly solve it.
1. Projectors Aren’t Just for Presentations
Avoiding shadows can also be a problem in other situations. A projector setup that works for a presentation, for example, with only one person needing to point things out on the screen, may not work well if the image is something like an architectural drawing, that everyone in the room needs to point to and discuss. Similarly, you may need a display in, say, a reception area, where people will be standing up and walking around, and can easily cast shadows.
2. Look Ma, No Shadows
One way to avoid any possibility of shadows is to put the projector in back of a translucent rear-projection screen. The problem with rear projection is that you need enough room behind the screen for the projector to throw the size image you want. For a standard or even a short-throw projector, that works out to a lot of dead space behind the screen. For an ultrashort-throw projector, however, all you need is to wall off a small part of a room, or, better yet, put the projector in a small recess in the wall behind the screen.
Displays and Interactive Images
9. Interactive Images
Ultrashort throws open up a range of new applications for projectors. Hitachi, for example, pairs an ultrashort-throw projector with a touch-screen whiteboard, to give you a touch-screen interface with the ability to select menu options, draw lines by hand, and even handwrite comments. In principle, the whiteboard will work with any projector, since the interactive features are all handled by the whiteboard and its software. But only an ultrashort-throw projector will let you use the interactive features without casting annoying shadows.
10. Tabletop Image: Rear Projection
Another innovative use for an ultrashort throw is to project an image onto a tabletop. Picture a group of people sitting or standing around a table and discussing, say, a new product design, while looking at drawings laid out on the table. Now substitute a rear projection screen for the tabletop, with an ultrashort-throw projector mounted under the table and projecting the image up, onto the tabletop screen. Using projected images opens up possibilities, such as the potential to interactively rotate 3D images to get a better view, or show full motion video.
11. Tabletop Image: Front Projection
For projectors with a short enough throw, you can get much the same tabletop image if you stand (or permanently mount) the projector vertically on the table, facing down, so it projects its image directly on the tabletop. Put a touch-screen whiteboard on the tabletop, and you can even interact with the image directly.
12. Down and Dirty (On the Floor)
One last innovative possibility for ultrashort-throw projectors is projecting an image on the floor. Mount the projector in a safe place, next to or on a wall, for example, and point it down to project the image on the floor. This particular application is more appropriate for, say, a museum exhibit than for typical corporate use. (Although, a floorshow of company products on the reception room floor is a potentially eye-catching possibility). But it’s worth keeping the idea in the back of your mind, should you ever notice an opportunity to use it.