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The Light Board

Stanford Online's Lightboard Demo

Stanford Online’s production team has experimented with different techniques to display an instructor on screen while the instructor is writing lesson material on screen. The team has used the document camera approach, where an overhead camera captures instructors writing equations and drawing figures. They’ve also tried the “talking head” inset approach, where the instructor’s image appears in a small box in the corner of the screen. If you’ve taken an online course, you’ve probably seen one of these techniques used, and if you’re like most people, you’ve found the approach a little distracting.

Over the summer, the team caught sight of a light board that Northwestern University professor Michael Peshkin demonstrated on his website. Peshkin’s light board is made out of a sheet of glass that is illuminated by lights within its frame. An instructor stands behind the see-through light board, speaking as she or he writes on the board with neon markers. A camera films the instructor from in front of the glass board, but films the image through a mirror as a projected reflection, so the writing does not appear backwards. (The instructor image is a mirror image too, though, so southpaws appear right-handed, and vice versa.)

The production operations manager at Stanford Online, Wes Choy, likes to solve production challenges by building things— like the camera-mounted quadracopter that was used to film the rooftop solar panels in Stanford Online’s Nanomanufacturing course. He also likes to go the extra mile—even when that mile is straight up, like the summit of Pikes Peak in Colorado, where he kept filming…. despite feeling “woozy”… for the segment on altitude that is part of the course Your Body in the World: Adapting to Your Next Big Adventure.  So, Wes set out to not only to replicate Peshkin’s light board, but to improve the design too.

The team started with the base: Stanford physics department’s machine shop followed Peshkin’s website instructions to build the (approximately) 8-foot-by- 4-foot frame. They built a sturdier metal base, with dimensions that could fit through standard doorways at Stanford, and they added wheels so the light board could be moved around campus. Because light board weighs about 700 pounds and is top heavy, Wes asked the shop to add a buttress that could be extended and retracted from the base, just for added stability and safety.

Next LED lights, were installed that could fire up to 10,000 lumens. “That was pretty bright,” Choy said, “so we installed dimmers that we could adjust to get the lighting just light.”

 For the glass, the team found a very high quality material—Starphire, an architectural glass that has low iron content, making it optically clear. Other glass would likely tint the subject with a teal or blue tone. Next came the testing and integration with computer applications like PowerPoint.

 “Instructors can also project graphics onto the board,” said Neil Rogers, a Stanford Online course producer who worked on the project and conducted a lot of the testing. “If an instructor deletes the background of a graphic within PowerPoint or a graphics application, students can still see the instructor through the glass,” he said.

“I thought the light board was fantastic!” said Lisa Hwang, a lecturer in chemical engineering who used the board for an online component of a Stanford class. “The students really liked it and specifically mentioned that they appreciated being able to see my face. It also has a ‘wow’ factor that helps keep the students engaged.”

 “This is an innovative idea for video presentation,” said Brent Izutsu, director of digital media at Stanford Online. “It mixes traditional teaching styles with new technologies for a more engaging learning experience.”

 The next problem to solve was the clean up: When the board becomes full, producers can stop the camera, clean off the board, and then restart filming.

 “One thing I’ve learned is that glass is never clean enough,” Choy said, turning up the lights on the board during a recent team demonstration to reveal fingerprints and smudges. “So I’m experimenting with cleaners. The neon markers leave oils, and believe it or not, dishwashing soap is good at getting out the oil, but I’m still looking for that perfect solution.”

 Up next on the team’s agenda is to build out the studio space. Currently, the light board resides on the ground floor of Lathrop Library, in a relatively small room draped with black curtains.

 “I’m looking forward to moving it to a much larger space where the black walls and depth will create a look of infinite space behind the instructor,” Choy said.   

 The Stanford Online light board is designed for HD filming, with a 16X9 aspect ratio.  Look for the light board in Stanford Online’s new courses that will launch in the middle of 2015.


Published: December 18, 2014

Source: The Office of the Vice Provost for Online Learning

For more information: 

Judith Romero, Stanford Online, (650) 725-7289,