Posted by: Brad Nixon | June 18, 2010

Behind the Scenes: Video

As we prepare to stage the company’s big annual events, I hope you will find it interesting to know some of what goes into making a show happen. This is the fourth in the series. Scroll down to see previous entries on the Load-In, Lighting and Audio.

Every picture tells a story, and, at the big conferences, the pictures are my favorite part of telling the story. At our conference, we get to make big pictures in high definition.

The images on the screens (there are four large high definition screens in this show) come from a variety of sources: video tape, computer and live cameras. Each point of origin has its own “world” backstage behind the set.

Video World

Video World

Back of Video World

Back of Video World

Here is a portion of “video world:” racks of video tape machines for playback and recording, and the associated processing equipment. This is another instance of how the hardware components of the show arrive already “racked” into cabinets which are also the shipping cases for the gear. When the gear arrives, the cases are opened up and the components are wired together, which, as you can see in the photo, is not a job for guesswork. In this show, we are still playing and recording video from and to tape, although this is a fast-disappearing convention. Many shows now run entirely from digital sources, and I suspect that next year we may be doing the same.Graphics World

Another source of much of the programming is from PowerPoint, Flash and other graphics software. A team of people work backstage in “graphics world” before and during the show to assemble many individual presentations, interstitial graphics and sequences, cueing them from a presenter’s script or following an electronic signal transmitted by a speaker holding a small remote control. This little handheld device has a longstanding historic technical term: the pickle. In ancient times, the pickle did actually send an “advance” signal to 35mm slide projectors. Today, it typically turns on a green light in graphics world, telling the crew to advance to the next image. But it’s still a pickle.

Why so many computers? First, every computer has a backup which runs in sync with the machine that’s sending out the live signal. If a computer fails in any way, the crew member on the master control can immediately switch to the backup. If that backup computer fails, it results in a situation for which the technical term is SOL. There are at least three unique sources so that we can display multiple diverse images on the four screens simultaneously. That requires a lot of computers backstage. It requires not just extreme graphics skill, but extreme focus as well to work in Graphics World when the cues are coming quickly.Another source of video is from live cameras in the meeting room. These serve two purposes. First, we record the programs, in order to provide recaps of the presentations for people who were not in attendance. In addition, because the room is large, we may want to display live video of speakers or other onstage action on the screens in the room, particularly during awards presentations or when there are panel discussions, so that the audience can have a better view. That’s called IMAG, which stands for “image magnification.” In addition, we are webcasting part of the proceedings, so the signal from the cameras also goes into a webcast channel.Video console

A camera director sits at the console above, giving directions to the three camera operators, telling them which shots to get, and simultaneously deciding which picture to send into the “program feed” at any moment. That is a role for extremely focused people, able to juggle separate streams of information simultaneously, and to make rapid-fire decisions. Our 3-camera show is relatively simple compared to the large setups you see at sports events, but it’s live, and the pressure is always on.

Okay, with all these sources, how does one image get to each of four screens, in any combination? Out at the back of the house, where we’ve already seen the lighting and audio consoles sits the Technical Director or “TD,” who’s working from a “show flow” that shows all the speakers, videos, graphics, light cues, audio cues, etc. Another job that requires a lot of intense concentration and preparation.Backstage, a miraculous device with the brand name “Spider” combines all those video signals and routes them to projectors. I failed to get a photo of the Spider. Sorry. Another impressive mass of buttons, displays and doo-dads. Has its own operator, too. Not a device for the unschooled.Projectors backstage

These are not your average projectors. They project impressively brilliant images in high definition. You’ll notice there are two. They’re both on, projecting identical images. The primary reason to have two is redundancy in case one fails. But the doubling helps them produce an awesomely bright image. There is one pair like this for each of the four screens, eight in all. They’re stacked on these scaffold towers at a precise distance from the screen, for focal length, and at the exact center of the screen.

Convergence grid

In order to make the two images appear as one, the projectors have to be “converged.” Above you see one of many screens the projectionist uses to align the images precisely together. The projectors have an array of processors that will warp the image until everything is completely focused, square and aligned. In addition to the “shape” of the picture, the images have to match exactly in color, too. This process has improved with new generations of projectors. In the early days of video projection (not that long ago in terms of my career), converging projectors might require many hours for the projectionist, working alone in total darkness in the hall after all other work had ceased.

You have noticed that the projectors are behind the screens. That’s pretty standard in the biz, unless there’s no room for them behind the set. Projectors need a certain distance to throw an image of a given size. The bigger the image required, the more “throw” distance required. There’s math for that, worked out in advance. This rear projection (“RP” in the biz) brilliant sharp results on these screens which, technically, are very specialized lenses. They are flexible material, mounted in a frame. Like everything else in this business, they’re expensive, too. Well, let’s walk out into the house and see how the place looks now that we’re projecting a stream of light out there.

Lights, audio, and picture

Finally: pictures! See? Wasn’t that simple?

When we resume, the Global Jam rocks!

© 2012 Brad Nixon


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  1. Love the video of your Video! Had no idea!


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