CBS, Turner Sports Put 4K to the Final Four Test
NCAA Final Four weekend last month will be remembered by the production teams at Turner and CBS Sports as 4K weekend. The two entities worked together to capture the action in 4K and even display it on LG Electronics Ultra HD sets from located in suites at the Georgia Dome.
“We started hearing of 4K sets’ becoming available, so, at one of the meetings, the idea was to see if there is something we can do with our partners to highlight 4K,” says Tom Sahara, senior director, IT and remote operations, Turner Sports.
He describes the production process as “back to basics” because it quickly became apparent that not all of the production tools were available for end-to-end production.
“When we started looking at the technologies that were available, we started to see that there isn’t much,” explains Sahara. “The cameras are pretty far along, but everything else was on the bleeding edge, as much of the product was still to be introduced at NAB. We had to navigate that uncertainty as, aside from the standard 3G routing switchers, there was no way to do switching. We basically decided to record the camera feeds.”
And even getting those recorded signals into the four 84-in. Ultra HD sets was difficult. The HDMI 2.0 standard, which will allow 4K signals to be delivered via an HDMI input on the sets, is not yet complete. To get the signals to the sets, the signals were delivered from the compound to 3G media converters, which converted them to an HDMI signal that could then be passed through display cards to the Ultra HD sets.
The production itself centered on two Canon 4K cameras, with one located in a typical high camera position coupled with a large lens and a second, portable camera used for B-roll material.
“We wanted to show 4K pictures that people could relate to, not beauty shots or scenic shots,” says Sahara. “So we shot B-roll of banners and the exteriors of the Dome.”
The two cameras were paired with AJA Ki Pro Quad and Gemini 4:4:4 digital recorders and Apple Final Cut Pro editing systems, which were set up at one end of a production trailer, obviating the need for an additional mobile unit.
“We captured footage off of the cameras in both of those, recording Apple Pro Res in the AJA so we could test editing workflows,” says Sahara. “And we recorded raw images in Gemini so we could look at the quality and test a cinema workflow using the DPX, or Digital Picture Exchange, file format.”
Recording began on the Friday of Final Four weekend during the All-Star game. That material was turned around for display during the semifinals on Saturday night, and footage from those games was turned around for Monday night’s final.
“We were dealing with RAW recording, and every frame is 33 MB, so it took time to copy the content from the drives [into the NLE] and then render it out,” says Sahara. “But we were able to get the content off the camera, transferred, converted, and edited overnight.”
One aspect of the Ultra HD experience that was not undertaken was recording at 120 frames per second (fps). Prerelease hardware locked to 30 fps meant that 60-fps recording could be done only in the Gemini recorder. Even the LG sets are still in prerelease mode and do not yet support 60-fps viewing.
“We were very aware of the frame-rate issues shooting at 30 fps, and trying to do a full production would have highlighted those issues,” Sahara explains. “So, in the end, we did the right thing, which was to frame each shot in the best possible way [for 30-fps viewing].”
He adds that the viewing experience and reaction from people in the suites made the efforts worth it.
“We made a 20-minute loop, and we saw people watching it three times in a row,” he says. “And you can sit about 1.5 times picture height away from the set and have a comfortable viewing experience where the screen fills the field of view and you can see lots of details.”
Among those details? The grain in the wood of the floor and the ability to pick out celebrities sitting on celebrity row from a camera capturing an image that was slightly tighter than half court.
“The talent and celebrities were easily recognizable, and those sorts of subtle differences made the picture more life-like,” says Sahara.
The production also laid bare the biggest challenge of all in the move to 4K: going from an HD production world, with ⅔-in. sensors providing infinite depth of field with very good resolution, to full-frame sensors that provide a shallow depth of field with four times the resolution.
“You have to study what you want to do and figure it out; you can’t guess,” he explains. “We were using a 30-300mm lens where our minimum object distance was 18 ft., but, with HD, we are accustomed to having an MOD of more than 50 ft. so that both the near and far side of the court are in focus. So, with 4K, we had to decide which side of the court is in focus and picking the right f-stop to get the right depth of field. Those who have done a lot of film and photography work understand that, but it’s going to be a big learning experience.”
That will also mean more reliance on focus-assist technologies and, of course, systemization of cameras currently designed primarily for cinematic shooting into ones more suitable for live production.
“Being able to capture, turn around, and display 4K content on a consumer devices at this stage of 4K development was pretty amazing,” says Sahara. “In the early days of HD and 3D, we had to go through endless steps of production and conversions. But here we were able to do it all with off-the-shelf components.”