4K and the Future

NAB 2012 is just around the corner and it seems the buzz this year is going to be 4K. Last year it was 3D, and this year it’s 4K. RED has been there for a while and Jim Jannard has been calling 1080P a “mistake” for years. Now Sony and Canon are jumping on board and others are sure to get into it too.

So then does this mean that 4K is the future, or in fact if the cameras are here now – is it the present?

The answer to both questions is yes! And also no.

Lets step right back to fundamentals and ask a basic question – what is 4K? Unfortunately it’s here that we hit the first (and biggest) hurdle. 4K, at the moment, is basically whatever a camera (or display) manufacturer wants to say it is. The DCI defines 4K as 4096×2160 at most (with actual height being a product of the aspect ratio), while RED’s 4K is 4096×2304 or 4096×2048 (depending on aspect ratio). Many other companies are adopting the Quad-HD format – 3840×2160 – twice the height and width of 1080P HD and still other 4K standards have been based on other “close to 4000” frame sizes. But overall there’s no one standard framesize that we can call “4K”

However it’s clear that 4K technology is here, but it’s not all here yet. When HD finally arrived in a meaningful way there were two basic variations – 1080i and 720p. Two framesizes each with a distinct scanning pattern (interlaced or progressive) – it was complicated by various framerates (23.976, 25, 29.97, 50, 59.94 etc) but overall there was a standard. A Sony camera could be connected via SDI cable to a Grass Valley vision mixer and recorded to a Panasonic VTR. This is not true for 4K. There are no firm standards addressing how a 4K picture should be transmitted over a wire. Monitoring, offboard recorders, projection – all rely on a handful of ad-hoc solutions wedged around existing formats and standards. HDMI is the closest we have to a usable standard for 4K video connectivity – and HDMI is not practical for most professional applications.

There’s also the matter of demand. There is currently no distribution system for 4K (beyond DCP for a very limited digital projection market). RED want to change this with RED Ray, but they are working alone on that and I’m sure we can recall how Beta/VHS and Blu-Ray/HD-DVD hampered technological advancement. Currently there are no broadcasters, distributors or film festivals that demand (or accept) a 4K deliverable. Of course that’s likely to change, but without standards, formats and platforms for that distribution, the demand is going to take a while.

But, of course, more cameras are starting to appear, I/O hardware is starting to offer various 4K support, and NLE software is also getting there. But for what? Only an absolutely tiny fraction of a single percent of the projects created with RED’s cameras in the last 5-6 years have been finished at anything greater than HD (or 2K). Jim Jannard will argue about the future viability of those projects – suggesting that a new 4K master could be created from the original source once the demand arrives (and HD is considered not good enough), but in reality for most it’s unlikely that the terabytes of source footage will been suitably archived to make that possible.

So what is 4K for now? 4K now is for HD. A great 4K image makes an even greater HD image when it’s downsampled for the smaller frame – this is the idea behind Canon’s C300 camera which does this internally. Also a 4K image provides a lot of scope for reframing in post-production – a shot can be “zoomed in” approximately double before new image data has to start being created.

Do you want to get into 4K? Maybe, but spend a bit of time first thinking about how and why you want to do so. It’s incredibly unlikely that you’re going to face a sudden need to actually deliver 4K images. The technology that seems great now may not be at all suitable when you are finally faced with a need for a 4K finished product – if, for example, we end up settling on 4096-wide frames for standard 4K then footage acquired with the Quad-HD format would need to be blown up to fit.

If you are doing work that frequently sees you needing to re-frame shots in editing then a 4K camera may be really beneficial. That was the first application of HD for many producers – allowing footage to be zoomed within SD projects.


  • http://www.thestudioshop.co.za Derrick van Niekerk

    He he, if you’re gonna reframe that often, then you should learn to compose better, or maybe plan a bit more !?

    4k is cool and all, but everything is just getting comfortable with 1080p, let’s enjoy that for a couple of years first. 1080p is very capable of capturing plenty details. infact, has anyone thrown away there DVD’s because the movies just look crap now? No, we still love plain old SD DVD plenty.

    just my opinion,

    • Dylan

      1080P is actually an interesting case. Even now, many years after wide-spread adoption of 1080 HD the true progresive form is still barely in use. Almost all practical implementation of progressive 1080 are in fact PsF (progressive segmented frame) – essentially a progressive image in an interlaced signal. Simple HD-SDI isn’t up to the task of 1080P video, so either dual-link or 3G-SDI is required, both are now more widespread, but we’re still not much closer to seeing true progressive 1080 video being pushed around.

      • http://Www.brandedchannels.com Richard

        Funny thing is that I’m currently working on a project I shot on DSLRs and edited in 720p @25fps. Client wants a blu-ray as well, but it turns out that 720p is only supported with 24 or 50fps according to the spec. Since conforming from 25 to 24fps does not seem like a good approach to me, I opted for rendering out to 50fps. I also heard about PsF techniques, in which you can wrap a 25p signal inside a 50i stream, but since don’t adhere to the official spec, it may not be supported by all Blu-Ray players. So much for standards…

        Do you know if Blu-Ray players in USA will play 720/50fps content without problems?

        • Dylan

          The “PAL” 720P format is always 50P officially – the standard way to display 25fps material is frame doubling. I believe Media Composer and some other software can cope with this internally. Otherwise your compression software might be able to correct it.

    • http://davidvosburg.com David Vosburg

      Personally, I find myself doing a fair amount of motion graphics and After Effects work in 720 so that I can do interesting things re-framing 1080 footage. 4K allows for a higher output, yes, but most of my clients aren’t looking for that. What it makes possible that interests me is far more dramatic post production leeway in a compositing context.