Big, Bigger, Biggest – 4 benefits of 4K

By October 28, 2015 Blog
3dcinema-darken

Tech Tips by Leigh Ockey, Metro Screen Hire and Post Production Manager.

 

8K is on its way! NHK have long been developing 8K cameras, RED have the Dragon Weapon, and Canon are getting into it with an announcement about the 8K products to be looking out for if you were thinking about a second mortgage. Other manufacturers will reveal their 8K plans soon, so surely this means that the vital tool for filmmakers is going to be the latest and greatest camera that shoots 88 miles per hour on a 1.21 gigapixel sensor. Right? Well before we travel back to the future lets take a look at something a bit easier to comprehend. 4K

The bottleneck on 4K is still distribution, but it won’t be for long. Downloadable content over IP has won the race with streaming. The Hobbit was pushing cinemas to upgrade to high frame rate 4K projectors, and other platforms are being dragged kicking and screaming into the future too. So when it comes to finishing your film, series, or short the likelihood of needing 4K isn’t high. Yet.

While SD to HD took 10 years to shift, 4K has been anticipated to take just 2.

The expectation of having all-digital content delivered instantly as opposed to waiting for a DVD or Bluray has dramatically sped up the adoption rate for 4K, and clearly, this adoption is happening faster than SD to HD adoptions that took over a decade. Digital movie purchases jumped 47% in 2013 while DVD and Bluray sales and rentals have slumped-and this trend appears to be accelerating.
-Quantum Report “Preparing for 4K Content Workflow Transition

But if you live in hope that Australian television will be broadcast in UHD then you’ll be waiting a very long time. We’re still watching 720P and on some channels even SD programming. The development of h.265 for encoding media is already being put into commercial devices including mobile phones to play content at roughly half the bandwidth. The expectation is that most TV will be broadcasting h.265 by 2023, but for Australian Television this is predicted not to mean upgrading to 4K, but additional channels. Hooray for more midday re-runs of The Voice!

There are plenty of white papers, tech talks and random blogs that explain in varying levels of truth about whether 4K (or 8K) actually matters. And for the most part audiences can see the difference when they’re told to look for it. If they’re close enough.

resolvution chart

The further away the viewer is from the screen the less resolution the human eye can perceive, therefore screen size must get exponentially bigger. So we’re now all moving our couch to within 2m of the 50” 4K. Those of us with 4K displays in the lounge that is. Time to leave the resolution discussion aside and move onwards to the 4 benefits of (recording) 4K.

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That looks better, but not because of the obvious

What is really exciting about 4K isn’t the bigger frame. The development of 4K standards forces technology to accommodate for higher bandwidth (the total amount of information processed at any given moment) and with it comes bonuses for image quality.

UHD benefits

Bigger colour space (DCI is the existing standard for cinema and Rec.2020 will be the goal for UHD) will mean brighter vivid colours, and that doesn’t equate to the oversaturated eyesore that you get when your TV is set to “dynamic”. 10bit colour means smooth gradients remain smooth, rather than becoming blotchy. High Dynamic Range (HDR) simultaneously underexposes and overexposes to retain detail in both shadows and highlights. Getting the best out of HDR involves blacker blacks and brighter whites. There’s also high frame rate, but personally I don’t see the appeal.

Advancements towards standardizing 4K is important because display technology will have to reach a benchmark before being permitted to carry these labels. The end result is that your image will look more like the footage that you shot, edited and graded, instead of adopting the DV camera look for exhibition.

4K and UHD is not solely about a larger frame, it is an overall improvement in viewing experience.

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Low budget FX no longer look low-budget

If you’ve done chromakeying on a cheap camera you’ll be familiar with the dramas of HD special effects. More colour information, smoother gradient and bigger resolution means better keying: crisp clean lines, not losing blonde hair, and honing in on spill where before you lost half of someone’s arm.

 

It also means greater detail available when tracking an object. The likes of After Effects and Davinci Resolve have automatic tracking that can save a lot of time, but often get confused if the action is unpredictable. More information for these trackers means they are always accurate (within reason). And composited elements slide in to your footage a whole lot easier with more pixels. Often the downfall of generated elements is not blending in to the footage, resulting in a soft cityscape with an incredibly detailed scaly Godzilla foot.

The most important thing for 4K FX work is to have a codec used throughout the post workflow. An uncompressed 4K stream can demand more than 1GB of data every second. The lossless option is to edit using the original camera files or from a digital master that is larger than the footage like ProRes or DNxHR. Depending on the size of your project and how much time you have in your post schedule you will probably need to create proxies to edit with, most likely in 2K. For graphics and grading you would be returning to the source or digital masters to leverage the benefits of 4K, then sending your Master Export ready for compressing into deliverables.

The alternative is a Mezzanine format, which is much friendlier on your computer, by converting originals to a format that holds enough quality to compress later, like Cineform or h.264. If your bitrate is higher than 100mb/s this may be considered “visually lossless” however you will be losing quality that you DON’T see that reveals itself during grading or FX. However you would be able to edit from ingest to export without transcoding, saving time.

When choosing your format, whether Original, Digital Master, Mezzanine or Proxy, match your process to your end game. What format does your master deliverable need to be in, and where are you doing the bulk of your post production? There’s a best-fit codec for every project so long as you think about it before the camera rolls.

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Shoot in 4K because it will make HD look GREAT

We had the opportunity to perform some detailed camera tests on 4K camera phones. Such advanced technology in something that you store next to a bobby pin and some lint is mind boggling. But the test results were not that surprising. The UHD (3840×2160) footage definitely looked better than the HD footage. Just not THAT much better when compared to another phone brand that only shot in HD.

What we did observe was that shooting cheap 4K and squishing down to 2K made for some really good 2K. For the same reason that really expensive cameras shooting HD have a sharper image than cheap cameras, just because it claims 1920 pixels doesn’t mean the camera’s sensor is resolving information into each pixel.

The golden benefit of scaling 4K down is that you can make a REAL cinemascope 2K instead of letterboxing HD. Because we make lots of DCPs we see all manner of bad practice when it comes to finishing a film. If you are hoping to screen in a cinema then please read our DCP Tips.

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None of your hardware will handle it

This one isn’t a benefit at all but is more important. Don’t shoot 4K (or 8K) unless you have planned your post workflow. In 2 we mentioned picking codecs based on your master deliverable, but the reality is that most of the time your workflow will be based around capability. If you’re not pimped up with 64GB ram, quadcore processing, 4K graphics card and accelerated GPU then…

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Don’t record anything (except tests) until you have a plan. The immediate thing you’ll notice with 4K is there’s a whole lot of data. But beware! Not all hard drives are equal. Before buying external hard drives do some research. There’s a few websites where you can look at reviews and benchmarks of products. Look out for real-world testing by users rather than trusting claims from the manufacturer. Your main editing hard drive(s) will have to be good, possibly sacrificing capacity for read/write speed, or spending more than you expected. You will want to have the quickest connection when working with 4K sources. If your project is large you will probably want to have something like a Promise Pegasus which has incredible read and write speeds as well as RAID setup for peace of mind.

When it comes to backups the cheaper HDD options will be fine because speed is not as important. Most brands have very low failure rates, but you can’t guarantee anything, so it’ll be better to have two cheaper drives than one expensive one, especially for backups.

Your workstation is either going to need replacing completely or you should have a planned post workflow that makes use of a post production facility for ingesting and onlining so that you’re able to edit without constantly watching that spinning beach ball (or hourglass). If you do intend to edit in 4K and have the GPUs to prove it, a beneficial purchase is a 4K I/O device like Blackmagic UltraStudio 4K so that your graphics card doesn’t have to do all the work to put an image on the screen. If you’re thinking about building your own workstation there’s some info available from Videomaker.

 

Currently shooting big still has its benefits while distribution hasn’t yet caught up to 4K. But the day will definitely come when you have your nose to the screen staring at a blurry section of your image wondering why you didn’t shoot 32K. While 4K content isn’t everywhere, shooting 4K can offer amazing benefits for HD deliverables. So with that in mind, do you think 8K is for you?