02 Jan 2018

New resolutions: the technology that wins isn’t always the best

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Are higher resolutions really inevitable? Are higher resolutions really inevitable? Shutterstock

Index

It makes sense to originate at a higher resolution than we deliver – or does it?

There are good arguments for shooting at a higher resolution than you want to deliver – certainly the ability to re-frame is a genuine advantage for acquisition at a higher resolution and a strategy that many have adopted.

I would hesitate to endorse the view that it is necessary to originate at a higher resolution for the best quality. The fact that the Arri Alexa didn’t quite manage 4K resolution didn’t seem to hold it back from being acquired for motion picture shooting.

I believe some of the arguments in favour of originating at a higher resolution are actually a hangover from analogue days when quality was diminished at every stage of the process. But if your delivered image is 3840 × 2160 or 3996 × 2160, you are not going to get any more pixels – in fact, by downsampling you have added more processing to the stream which could, in theory, create more artefacts.

There is a general notion that your final image looks ‘better’ if you shoot at a higher resolution image than you intend to deliver. OK, I am not an engineer. I’d just like to know why. A scientific explanation please, not just an anecdote about the particular camera you use.

It is not just the number of pixels

In the consumer marketplace, high resolutions are an easy sell. HDR is harder to explain, colour sub-sampling is probably something about which consumers would prefer to remain ignorant. But we should also be considering how much that picture is compressed. Many video cameras offer 4K resolution at the price of higher compression or lower bit depth.

We are unlikely to be working in 6K or 8K at 4.4.4 uncompressed, so there is a trade-off between resolution/compression/colour sub-sampling/gamut/bit depth/frame rates – increasing the pixel count is not the only game in town.

It’s not just about picture quality

And this, to me, is the most crucial point. An obsession with resolution can distract from what this business is all about, which is telling stories.

Throughout the latter half of the 20th century, cameras were getting smaller and lighter. This, at the time, was considered a breakthrough in how films could be made – you could shoot fast on location with smaller crews, you could use documentary techniques to capture performances spontaneously. Now, higher resolutions don’t necessarily mean bigger cameras, but the trend towards larger sensors has brought with it bigger lenses and bigger rigs and a reversal of that trend. Perhaps this is a reaction to the fact you can shoot a movie on your phone – directors distance themselves from the world of YouTube.

My predictions? 4K will become more or less the norm for HD delivery. Broadcast will gradually shift from HD to 4K post production as standard, the speed at which this happens depends on the wider TV landscape and whether the rise of the streaming services continues. I don’t see resolutions higher than UHD becoming a standard format for home viewing in the foreseeable future. 4Movie distribution will settle down to 4K but acquisition may shift to 6K or 8K depending on the project. And on which camera Arri launches next.

But, as always, I could be totally wrong.

Image courtesy of Shutterstock.




Roland Denning

Roland Denning is an independent filmmaker and writer based in London. He was a lighting cameraman/ documentary cameraman for two decades, shooting everything from feature drama to rock promos. He still shoots when he can't afford to employ anyone else. His satirical novel, The Beach Beneath The Pavement was published in 2011.

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