A Slo-Mo Primer: More Frames, Options and Fans

Related: 4K Shooters Multiply

Even in a hyperactive media and television landscape, slowing things down can have its advantages.

Or so broadcasters are discovering as they deploy the newest generation of slow-motion cameras. Not only can these cameras take viewers inside games in ways that wouldn’t have been possible even a few years ago, in a number of cases, high frame-rate cameras can even replace regular cameras, providing producers with added flexibility to capture either slow motion or regular images.

“Networks are really adding more slow-motion cameras to liven up their coverage,” says Tom Dickinson, CTO at Bexel, a broadcast services company that works with several major networks on their sports productions. “We have almost doubled our inventory [of slowmotion cameras] and will be increasing them some more to about 15 cameras,” he explains.

Dickinson says there is particularly high interest in newer cameras such as the Sony 4K F55, which is being used for 4K replays, or the Grass Valley LDX 86 XtremeSpeed Ultra Slow Motion HD camera. But there is also growing demand for ultra-slow-motion cameras that can operate at 1,000 frames per second or more.

“We have sold probably 80 or 90 systems since we launched the Hi-Motion II cameras in 2012,” says Andy Hayford, international sales manager at NAC Image Technology, which worked with Ikegami to develop and launch the ultra-slow-motion camera. “Back in 2008, there were probably only 30 to 40, so there has been a huge increase in acceptance.”

Laurent Renard, CEO and founder of IMovix, which produces the X10 UHD superslow- motion camera that ESPN and a number of broadcasters use—which adds improvements in both camera technologies and workflows—is driving increased interest among broadcasters.

I-Movix, for example, has closely integrated its cameras with Evertz’s servers so producers can get quick access to both a live HD feed or super-slo-mo 4K material. “We can replace any standard camera shooting at 25 or 30 frames per second and on top of that do super-slowmotion at 3 times, 6 times, 10 time or even go up to 1,000 frames per second,” he says.

Quick Turnarounds

Two key developments allowing for all the versatility have been rapid improvements in processing power and sensors. Progress in those technologies has been so rapid that the new Apple iPhone 6 is able to shoot very high quality HD video at frame rates as high as 240 per second—twice the rate of the iPhone 5s.

Another important factor has been connectivity. ‘We are now able to work in live production conditions with huge amounts of data,” says Renard.

Klaus Weber, senior product marketing manager for cameras at Grass Valley, adds that their third-generation transmission systems bring digital triax and fiber into the same bay station for cameras, making it easier to transmit the large volume of material produced by slow-motion cameras.

Grass Valley has also moved to CMOS sensors— as opposed to the CCD sensors traditionally used in broadcast cameras—when it introduced its new LDX line in 2012, Weber adds. With that introduction, it also developed systems to overcome the “rolling shutter” problem that had once reduced interest in CMOS sensors.

“They’ve allowed us to take the image quality to a new level,” Weber says. “They outperform every CCD by 30%.”

That’s no small feat because higher sensitivity is crucial for slow-motion cameras with much higher frame rates. “The best CCDs could do 3X [three time faster than typical frame rates] at 1080i but could not go to 3x at 1080p,” he says. “But you can go higher with CMOS because they have much better sensitivity and dynamic range.”

The new Grass Valley LDX 86 XtremeSpeed Ultra Slow Motion HD camera has also been designed to overcome some of the workflow and technical issues created by the fact that higher frame rates produce a much larger stream, which requires more storage and can slow down the turnaround for replays.

To overcome that problem, The LDX 86 has wider 10GB fiber connections. This makes it possible to send back a regular HD and a higher frame rate 3X or 6X slow-motion feed to be recorded on three servers using regular broadcast workflows.

That possibility is convincing some producers to replace regular cameras with slow-motion cameras capable of sending back either a regular HD video or a slow-motion feed. “I’m not sure if they would ever completely replace them because of the added expense,” both in the cost of the cameras and the need for additional storage, Weber says. “But if you typically have 10 regular and one or two slow motion, now I think people are looking at eight regular and four slow motion for greater flexibility.”

Higher-Res Replays

Those storage and workflow issues are particularly important as producers make greater use of 4K or UltraHD cameras with slow-motion features for replays.

“Over the past year, 4K replays have become commonplace in most major professional sports,” says Toni Lucatorto, cinema product manager at Vision Research, which launched the Phantom Flex 4K camera that has been widely used in production of sports, film and TV commercials.

“The most interest is in sports—in boxing, football and horse racing, where they are using a 4K camera to create a 4K image and zoom into an area,” adds Jay Shinn, VP at For-A America, which produces the FT-One 4K super-low-motion camera that delivers a simultaneous 4K feed and a HD feed for live viewing and playback. “It gives you much better resolution so you can see, for example, whether a foot is inbounds. Having a high frame rate 4K camera reduces the motion blur when you play it back.”

To make the camera easier to use in traditional broadcast settings, For-A introduced a number of improvements in the last six months, including fiber I/O connections built into the unit and the new ZE-One 4K extraction system for framing and producing HD replays from the 4K image. “It makes it easier for users to easily zoom in and out,” Shinn says.

Workflows and ease of use were also top of mind in the development of the Hi-Motion II by NAC and Ikegami. Partnering with a longestablished producer of broadcast cameras means that “all the camera controls, fibers, communications and workflows are industry standard,” Hayward says.

“It means that it sets up and is as easy to integrate as a traditional camera,” adds Alan Keil, director of engineering at Ikegami.

Improved censors will make further advances possible as camera manufacturers work to overcome the light limitations that have traditionally restricted the use of slow-motion cameras. Hayford notes that improvements to the Hi-Motion II improved sensitivity by two to three stops.

Lucatorto at Vision Research adds that the Phantom Flex camera “has a low noise sensor that you can push in lower lighting and get a very good image quality, which is important in a lot of stadiums.”

“The quality of the image has been a huge factor in the [growing] interest, perhaps even bigger than the frame rate,” she says.