Selecting Projectors, Screens, and AV Switching Gear
Until now, I've discussed considerations for planning equipment in a room or for a portable show in generalities. Let's get into some of the technical aspects of choosing the right equipment.
These are the most important issues in selecting a projector:
Brightness (ANSI lumens). The brightness of a projector is determined on a standardized scale. Usually, the bigger the projector, the brighter it can be. Brighter means hotter, though, and a larger fan with a larger case to keep the bulb cooler. There are smaller projectors with bright bulbs, and the higher price tag reflects the cooling technology implemented in those units.
What's a lumen? ComputerUser.com's High-Tech Dictionary defines it this way: "A unit of measurement of the rate at which light is emitted from a source. The International System unit of luminous flux, equal to the light emitted in a unit solid angle by a uniform point source of one candela."
For standards on brightness, consult the American National Standards Institute (ANSI), a private, nonprofit 501(c)3 organization that administers and coordinates the U.S. voluntary standardization and conformity assessment system.
We selected the Panasonic PT-L750U. It's rated at 3000 ANSI lumens and produces a very bright picture with all of the lights on. In our training room, that fact allows everyone to see their notepads to take notes. In our conference rooms, the natural light from the windows doesn't drown out the picture. Less than 3000 lumens in these conditions, and the picture quality diminishes. In a dark room, however, 1500 ANSI lumens can look bright.
Resolution (pixels). The only rule is that the projector's resolution needs to match that of the source providing the signal. Obviously, you can usually control the PC that you use with your projector. But what if you're meeting with a client or vendor who brings a notebook PC with a presentation optimized for 1024x768 pixels, and your projector only supports 800x600? Embarrassing situation. At a minimum, select a projector that supports 1024x768.
Inputs (number of sources attached). Our setup includes a built-in PC, guest PC, VCR, DVD, satellite TV, and auxiliary jack. Each of those could be used at any time. With a ceiling-mounted projector, you don't want to make adjustments to the projector while standing on top of a chair. We simplified matters by running all of our inputs through an AV switch (see next section).
Size/weight (important if the projector is portable). For our ceiling-mounted and cart-mounted projectors, size and weight weren't a factor. For our traveling checkout units, however, small and lightweight is very convenient. We have two units from Proxima, which is now owned by InFocus. They make great projectors.
I never knew that there were so many screen types and sizes. I didn't try to learn about all of them, because I knew basically what we wanted, but here's what I did learn. Screens can be sized in standard 4x3 television format, as well as 16x9 widescreen format, like movie theatres, and of course they come in various sizes. You can even get whiteboards that double as presentation screens. Plasma displays that double as TV and presentation screen are nice, but are still small and expensive. The most amazing kind I saw was a big-screen TV type of cabinet with a rear projection screen for which you could control the pointer with your finger. It's a unique idea that I'm sure has tremendous potential.
Our needs were relatively simple. We selected standard format and chose a 9' wide screen for our training room and a 6' wide screen for our smaller client conference room. The built-in screens have a switch on the wall with a simple up/down toggle.
When we do a portable show, our 6' wide traveling screen is simple to use: You just open the case like a suitcase and lift the screen straight up. Wherever you let go is where it stays. It works from the floor or on top of a table. When finished, it just pushes back down into the box. I never plan to use the tripod screen again!
An AV switch simplifies the built-in projector operation. You don't have to move cables to select each source. Instead, each device hooks to the switch, and one cable runs from the AV switch to the projector. We chose the Extron MediaLink MLS506. With its six inputs, we can run everything we need. At the touch of a button, it sends the selected video signal to the S-Video input on the projector.
The interface to the AV switch is simple. We added the MediaLink Controller MLC206. Backlit buttons on the switch tell you exactly which source is selected. To switch from one source to another, you simply touch the appropriate button. The switch automatically adjusts resolutions with the projector so that each image is displayed without distortion.
We also looked at more sophisticated switches. One ran from a panel built into the wall. When you touch the button, the screen drops, the projector turns on, the blinds close, the lights dim, and the selected source begins. This system was impressive and expensiveway more than we needed! The system we selected requires hitting three buttons: screen, switch power, and source. Closing blinds and turning off lights is still a manual process, but that's not a big deal to us.
Another impressive solution was a radio frequency remote that could learn the codes from all of your other remotes (VCR, DVD, and so on) plus control the projector. We opted for the simpler solution and saved quite a bit of money doing so.