The decision to go all-in on 4K is tough for viewers, but consider how hard it is for live broadcasters.

The Consumer Technology Association predicts a boom in sales this holiday season that will push the total number of 4K sets sold to 10 million in the US for 2016, a 40-percent increase over last year. That means demand for live events in 4K—sports, live news, The Oscars—will continue to grow. However, the companies who produce the live coverage will need to make a slew of expensive hardware updates—new cameras, new video switchers, new servers, new encoders, and new distribution platforms—to start pumping out 4K feeds. What's more, much of the industry has cold feet: They just got burned by 3D overhype, and even more equipment upgrades are likely on the horizon for 8K.

But fittingly, the UFC is up for the 4K fight. By the time a 4K TV is in every home, the UFC wants to be a well-oiled 4K production machine.

Come Out Swinging

In the past decade, the UFC's global growth and popularity has skyrocketed. Because of its pay-per-view business model (purchases of the UFC's live televised events make up the bulk of its revenue, and business is booming) the mixed martial arts organization is in a unique position to push forward on live 4K production.

The league has already produced live broadcasts of two pay-per-view events in 4K. Last weekend, the UFC 205 event in New York City drew $17.7 million in ticket sales at Madison Square Garden, a record for both the arena and the UFC. And while the number of pay-per-view subscribers for the event hasn't been announced publicly, UFC president Dana White hinted that UFC 205 also set a record in that regard. If so, then the event drew more than 1.65 million paid TV viewers, each paying $50 to $60 to watch the fights.

And some of them watched it in 4K, so long as they had the right hardware. The 4K feed was shown via satellite on DirecTV pay-per-view, and owners of certain Sony 4K TVs could stream the fights with a UFC Android TV app that delivered UltraHD video to compatible Sony sets. In other words, there are subsets upon subsets of a relatively small audience at play: UFC fans who order an event on pay-per-view, own a 4K TV, and have a specific Sony TV or DirecTV service with a 4K decoder box.

The limitations mean the UFC isn't expecting insane numbers out of its 4K viewership. But while the predicted 4K audience is a tiny sliver of the UFC's global pay-per-view subscriber base, they're still paying customers who demand a good viewing experience.

Executive VP of production Craig Borsari says it's important for UFC to try new technologies like 4K even though it isn't widely adopted yet. "If 4K adoption does end up hitting a critical consumer mass, we're already well ahead of the curve," he says.

Making 4K Magic

The privately owned UFC handles its TV productions with its own team, and the 4K show is produced separately from the HD broadcasts. They use the same cameras, on-air talent, and between-fight segments for both the 4K and HD shows. The editing, video delivery, and other aspects of production are done differently.

During UFC 205, there were eleven 4K cameras shooting footage inside the octagon and around Madison Square Garden for the event: Handheld cameras, cameras suspended above the octagon on remote-controlled robotic arms, and several fixed cameras shooting above and through the fence. All that UltraHD source footage was used for both the 4K and HD pay-per-view broadcasts. The multiple video feeds from inside the arena hit the 4K truck first, where they were down-converted to HD instantaneously and shuttled on to the HD truck.

The state-of-the art 4K production truck used by the UFC features dozens of monitors and comes with its own fleet of 4K cameras. Mobile TV Group

"The HD truck is the hub of the entire universe at our events," says Borsari. That will likely be the case as long as the HD production is serving the majority of the league's paid viewers. But the 4K production truck isn't just feeding video to the HD truck. It's a symbiotic relationship. For each fight, the 4K production team edits its own cut of the action. But when a fight ends early, the 4K truck receives a feed of pre-produced segments from the HD truck. That footage is all HD content, so the truck upconverts the footage for the 4K broadcast; those segments aren't full 4K, but they're sharper than HD.

While the live fights are edited differently between trucks, the 4K production team mostly "shadow cuts" based on directions for the HD broadcast. But to flex the full muscle of 4K resolution, they sometimes stay on certain angles longer than the faster-paced HD cut. That's to give 4K viewers extra time to appreciate the level of detail on their TVs.

Cutting the two broadcasts differently requires an extra camera feature. During live broadcasts, cameramen receive audio instructions from the teams in the trucks, but there's also a little light in the camera's viewfinder to let the cameraman know when a camera is "hot"—the active shot during the live broadcast.

But because of the different cuts between HD and 4K, a camera might be hot for the 4K production but not for the HD broadcast. So the 4K camera gets two lights: One for the HD broadcast, and another for the 4K broadcast.

That's not the only unique thing about the 4K cameras they use. Inside the 4K production truck, a team of video engineers remotely adjusts each camera's exposure settings. That allows the onsite cameramen to concentrate on composition and focus, while the engineering team fine-tunes things like color balance, aperture settings, and other aspects of the picture that are all the more visible in 4K. The light levels inside the octagon and in the crowd are hugely different, so these exposure adjustments are near-constant. "You can feel the motor on the lens (moving)," Borsari says.

Shortly after Conor McGregor knocked out Eddie Alvarez to win the lightweight championship at UFC 205 in Madison Square Garden, he was swarmed by a slew of 4K cameras filming the fight for pay-per-view. The UFC operates its own 4K live-broadcast production, which is a rarity. Jeff Bottari/Getty Images

The truck and the arsenal of cameras aren't owned by the UFC. For the New York City event, the company rented the state-of-the-art 39 Flex 4K Mobile Unit truck from Mobile TV Group. You don't just get a truck: Ten Sony HDC-4300 4K cameras and a Sony PMW-F55 CineAlta 4K camera were part of the package, as well as a pair of Grass Valley LDX-86s for capturing super-slow-motion footage. And obviously, you need a ton of monitors on the truck to support all those incoming feeds.

"There's 56 multi-viewers on the truck, but each multiviewer can have anywhere from four to nine images," says Dale Canino, director of technology for Mobile TV Group. "So depending on how they have it laid out, that number fluctuates. But I want to say 352 images is the maximum."

Mobile TV Group has a lot of experience in the short history of live 4K production, especially when it comes to sports. The 39 Flex truck used for UFC 205 has also been used at events like the Masters, Notre Dame football games, and BlizzCon. But that's just the production side; when it comes to delivering that sweet 4K feed to streaming boxes, the UFC partnered with NeuLion to encode and distribute the feed at bitrates low enough for at-home streams to stay stable.

Underneath the 4K truck—the belly of the belly of the beast—is a NeuLion 4K encoder that ingests the 4K broadcast feed, encodes the video on site, and zips it to NeuLion's cloud distribution platform.

There, the 4K video is transcoded to work with devices across the world, even if those devices are limited to Sony TVs in this case. That's because newer Sony 4K TVs have NeuLion's 4K SDK built into their firmware, although NeuLion senior vice president Charles Mellilo says more TV brands should be compatible soon.

Streaming To You

For now, the platform limitations are barriers for more viewers, but Mellilo says his company has made other important aspects of 4K streaming universally accessible. After encoding, transcoding, and compression, the 4K video feed requires a connection speed of around 18Mbps to flow steadily. While connection speeds are hit-and-miss the further you get from major metropolitan areas, Melillo says signs are good that most UFC subscribers can handle it.

"What we've seen is that users that are accessing it in 4K are watching the duration of the event in 4K," Melillo says. "That's important, because even though we're using adaptive streaming to ensure an uninterrupted experience, we're still seeing resolution staying at 4K."

And in maybe the most important corner of the 4K broadcast truck on fight night, three NeuLion engineers huddled around a monitor, eyes locked on an Android TV menu screen. They were the last-mile quality control technicians for the streaming event, making sure the pay-per-view feed was accessible at the right time and running smoothly. And they looked pretty bored.

"These are our engineers to ensure there's a steady feed ingest, and we like to say that if these guys have a very boring night, everything went as planned," Melillo explains. "We want them bored out of their minds."