Installation Profile: HD Distance Education
Sep 1, 2008 12:00 PM, By Dan Daley
University of Wisconsin's Pyle Center upgrade keeps its lead in distance education.
Classroom 235's audio was pretty good to start with. In addition to good acoustics from a band of absorptive material encircling much of the room at ear height, carpeted floors and the lack of parallel surfaces put its background noise level at around NC 25. These features, including the Gentner AP800 conferencing system, were all part of the original 1998 installation. The Gentner AP800 was upgraded with a ClearOne Converge Pro 880T system that features a built-in telephone interface and wide-bandwidth acoustic echo cancellation. Thirty-two Crown PCC-170SWO microphones and their cabling were left in place. Two new Shure UR1 wireless lavalier microphones and a new Audio-Technica U857Q AL gooseneck microphone on the lectern were added. Dascom's crews integrated the microphones with the Converge Pro system. The sound system remains stodgily stereo, mainly because the HDX 9004 codec doesn't have a discrete center-channel component. The revamped header space, however, has room to fit a center loudspeaker that could be placed to create an LCR array in the future.
“What was surprising to me about the audio on this project was the large number of microphones — 32 in all — and the fact that each one's talk switch is also a contact closure used to activate the cameras,” Facklam says.
Switching to high-definition video also required a new approach to lighting.
“When you have the opportunity for the instructor to wander around the space — and when you have multiple cameras feeding the video — you're going to have issues with shadows unless you light for them in the first place, and that becomes more so with HD,” Walker says.
Existing directional fluorescent lighting for the audience area is augmented by Brightline's broadcast-grade illumination system toward the front of the room. Illumination this bright would have washed out SD video images, but the higher brightness of the new HD projectors mean they can handle it and maintain good contrast. The audience light fixtures have 45-degree louvered slats; the Brightline fixtures are aimable and set at the same 45-degree angle as the others to focus more light on key areas. Based on where the instructor can roam in the room, pre-installation computer modeling determined the fixtures' locations.
Classroom 235 is highly automated in order to lessen reliance on live technicians, but you have to look carefully to spot it. Some of the more apparent manifestations of what turned out to be some very complex code-writing include a Vaddio pressure-sensitive pad at the instructor's lectern. When the instructor is standing on it, the video switcher is programmed to go to the camera aimed at the lectern from the front row of desks. If the instructor steps off the pad, the switcher goes to a wider shot from a ceiling-mounted camera. What students won't experience are dizzying pans as a single camera tries to follow the instructor around the room.
More subtle is how the Crestron e-Control system was programmed so that when a student in the classroom appears on camera, activated by touching the talk button on a microphone, the audio DSP will sense the end of a question or comment from the student and automatically switch the main image back to the camera covering the instructor. Even more understated is the fact that instructors can select one of three timing settings for this function from their own control point at the lectern, letting them determine the pace of each individual class.
“One of the overriding goals of the programming and the design of the room and the systems is to present the classroom as though it was a production, with the kind of basic production values you find in most broadcasts, like switched camera views instead of static or panned ones,” Walker says. “It's more like a show than a class, and that helps keep interest levels up.”
In a facility pioneering web-based H.323-codec educational videoconferencing when most others were still relying on ISDN lines, the leap to HD for in-class and distance education was intuitive. But like many pioneering propositions, it has roots that go back before the new technology was invented.
“The program here has its roots in public radio, which funded the early applications,” Poindexter says. “We have a background in patch bays for routing here, very hands-on. I think that really helped make this upgrade as workable as it is. It's not technology for its own sake, but technology that addresses the practical issues of education in a digital environment.”
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