Grass Valley says: “No compromise on live 4K”
Grass Valley believes it has found the solution to live broadcast-friendly 4K acquisition but it must hope the market doesn’t move from under it while it puts the camera to customer test. Ever since Sony decided to rework the digital cinema-designed F55 for 4K live production, Grass Valley has made noises about going another route. Perhaps it had no other option but to differentiate itself in the market.
At NAB, freshly injected with Belden backing and funds, it announced a 4K version of its popular outside broadcast LDX camera replete with three 2/3-inch sensors and use of standard B4-mount lenses. Some say it couldn’t be done, but Grass Valley has found a way — the result, says the company, of a belief that Ultra HD is about more than more pixels.
“Large format single sensor solutions are fine for digital cinematography but they have a lot of downsides for live in terms of a more restrictive lens system, reduced depth of field, poorer colour reproduction and less light sensitivity,” said Marcel Koutstaal, Grass Valley, Senior Vice President & General Manager, Imaging Product Group. Grass Valley’s approach is all about reducing those compromises, he said.
“If you want a 4K imager based on three 2/3-inch sensors which delivers 4000 pixels for each individual colour you have to make the pixels four times smaller than they are today and you would need four times more light coming into the camera. So that’s a compromise.
“Or you could put 4000 pixels on a much larger format sensor but to build an optical system with 4000 pixels each for red, green and blue in a large format would be too expensive. So that’s a compromise. Or, as you have a single large sensor and share the 4000 pixels per line across RGB (taking, say, 3000 green pixels, 1000 red and 1000 blue into a debayer process and output to 4K).
“We don’t believe any of those options is acceptable,” declared Koutstaal. “What we have demonstrated is the ability to take information from our current HD cameras into a 4K output.”
Not running a pixel race
He explains that the sensor in the existing LDX range already capture more data than it is currently able to output. By applying new video processing and debayering algorithms with a 4K output in mind “we can get the best results, that caters not just for spatial resolution but also different frame rates, dynamic range and colour gamuts,” he said.
Grass Valley is trialling the concept with sports live event companies this summer. “Depending on the results of those trials and market feedback we will bring the camera to market,” he said. “We cannot say when for sure at this time.”
There is a danger that further delay in presenting an alternative to Sony simply plays into the Japanese company’s hands. Outside broadcast firms are keen to equip for a wave of Ultra HD shoots anticipated by their clients from the end of the year, by which time Sony will have tuned its 4K production system over several more live applications.
“People are being overwhelmed with a 4K future but the business cases for live are still hard to make,” said Koutstaal. “We want to be part of the game with a business case that makes sense. Migration into live broadcast productions is starting slowly, because broadcasters need to identify a business cases. Our approach is to help broadcasters increase revenues with Ultra HD by choosing a product that doesn’t cause them to swap out their existing infrastructure and investment in items like lenses.”
Addressing high frame rates for Ultra HD sports will be key. To this end Grass Valley is working to leverage the software-upgradable high-frame rate capacity of its super slo-mo LDX XtremeSpeed 6X. Unveiled last IBC, this unit can deliver up to 360 fps.
“We have invested in HFR technology that can we can also leverage if also 4K goes to 100hz,” said Koutstaal. “We are not just running a pixel race. There are a lot of other areas where we will help broadcasters create better images with Ultra HD.
“We think the service industry needs flexibility with their investment and a smoother transition to Ultra HD. It’s great to buy a 4K camera but not if they are unable to use it in other applications. Grass Valley is format agnostic and cable (fibre or triax) agnostic. That is our mindset.”