Wednesday, November 12, 2008

Beam be down Scotty - CNN’s hologram

If you were flicking around their satellite or cable channels during the US election count last week, or surfing online and reading reports of the coverage, you’ll have come across CNN’s gimmick of the night.

The BBC’s Jeremy Vine had a green screen studio and stabbed his invisible touch screen. ITV had Jon Culshaw to mimic any guests they were unable to get in front of a camera. But CNN projected their Chicago reporter Jessica Yellin into their New York election centre studio by hologram! (Worth remembering that CNN was being broadcast in high def.)

CNN's election night hologram

It was CNN senior vice president David Bohrman’s idea, and much of the technical nous came from Vizrt and SportVU.

Take 1 green screen tent (called “Casper” after the friendly ghost), 35 HD cameras in a 220 degree arc, telemetry from the main studio cameras sent to Chicago so that a suitable angled image of Jessica could be stitched together and sent back for insertion into the main feed. Oh, and a 3 second delay for the segments of the show featuring the hologram to cut out the delay. Then break for an ad and reset the delay to nil.

SportVU originally started to develop their technology to allow instant replays to “orbit” goals at major sporting events and see the action from a range of perspectives. And in the end, the second holodeck built in Arizona near John McCain’s election night rally wasn’t used.

Broadcast Engineering logo

For technically interested or curious readers, Broadcast Engineering have uploaded a podcast interview with Vizrt’s director of usability Nir Goshen, discussing the mechanics of how they pulled off the hologram.

Turns out that the quality of the “hologram” was deliberately diminished. It could have been a close-to-HD image looking like the reporter was actually standing in the studio. But CNN took the editorial decision to make sure that viewers understood that it was a hack, and they followed the pattern of Obi-wan in Star Wars by adding white noise, faded edges and even gave it a glow.

The US are going through a Digital Switchover exercise at the moment, switching off analogue terrestrial signals (or replacing them with a test card message explaining where all the moving pictures have gone). Subscribe to the Broadcast Engineering Podcasts if you want to follow DSO progress in the US ... and they sometimes mention the UK too.

1 comment:

Timothy Belmont said...

This is totally irrelevant, but I was at school with "wee Johnny" Irvine of ITN news! I remember him well from school-days.