4K isn't just for movies and TV, it's for live theatre too.
That's the surprising message from Sony's digital cinema group and National Theatre Live, after the two staged the world's first 4K live to cinema event.
Even as patrons were filling the New London Theatre for another sold out showing of Michael Morpurgo's award-winning stage play War Horse, wannabe theatre goers were filing into the Curzon Chelsea cinema to watch a live transmission of the same show.
Cinema screenings of such live events are not new, but they've never been done in 4K before. This was a complete equine-to-end experiment.
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Six Sony F55 CineAlta cameras were capturing the show, uploading to satellite from the theatre and then beaming straight onto the screen in 4K resolution.
Before the transmission, David McIntosh, Director of Digital Cinema for Sony's Professional Solutions group, was optimistic: "The experience should be much more immersive, with 4K you can really feel like you're there."
For Sony, the event was to be a proof of concept, not to mention a precursor to this summer's World Cup. "We're looking to do the same with some of a selection of matches, delivering them 4K live into cinemas as well," he reveals.
But if you thought 4K was all about resolution you'd be wrong.
"It's actually about the democratisation and accessibility of culture and content," declares McIntosh grandly. "Wherever you are, you'll be able to see a live event in the highest quality. There's traditionally a barrier to getting people into the cinema to see things which aren't Hollywood blockbusters, but because it's 4K imagery onscreen, you can really feel like you're there."
As it transpires, the experience sits somewhere in between, a hybrid of the two.
4K has a sweet sweetspot
I actually ended up watching the first half just back from centre in the cinema, and the second half up front. The difference (perhaps predictably) was telling.
There's an undeniable relationship between detail and viewing distance that's crucial if you want to really appreciate the intensity of 4K.
During the second half of the show, I was picking up on nuances in performance and the texture in stage props that simply wasn't visible further back. The magnificence of Handspring's huge horse puppets became clear, from their translucent hides to their brilliantly engineered frames.
It's up close that the detail in a 4K image can really make an emotional connection.
This observation also holds true when watching 4K at home. Whatever size Full HD screen you're currently comfortable with, my advice is budget for something significantly larger when you invest in UHD, or at least move your seating closer to the display. Or both.
While the War Horse screening was a technical success it never quite matched up to the 'being there' hype. However, this wasn't down to the delivered image, more the thin and uninvolving sound that came with it.
While video fidelity is galloping ahead, it seems that Event Cinema audio still has someway to go.
What next for 4K cinema?
According to McIntosh, Sony's UK cinemas (along with those in France, the Nordics and the US) are now fully digitised, with many early adopter chains now looking to upgrade.
4K presentation is set to become ubiquitous, he says. "You can't stop the technology. Those that are entering that renewal cycle from first generation 2K projectors are definitely think about moving into 4K."
And after that? McIntosh's eye twinkle. "That's when we move to 4K laser projection," he beams. "Laser is going to be the next big step forward in terms of cinema projection…"