Creating and viewing video content in 4k resolution has never been more accessible. But don't go shooting in 4k just because you can, it might not be necessary. The process of delivering 4k video content as a videographer or filmmaker has certain limitations and changes in workflow that are worth considering before you hit the record button.
Before the comments fill up with critics of how important 4k content is against glass quality or sensor size etc., this article is will assume that these things are constant, your bitrate is sufficiently high for color grading, and your skills as a videographer are sufficient enough that you have charged for video creation.
The Cost of Data and Time
It’s quite obvious that shooting four times the number of pixels will eat more data than 1080p recordings. It’s important to be prepared for the increase data rate and memory demands. Whether it’s SD cards of SSD hard drives you are recording to, check that data read speeds are within the figures listed on the manufacturers website. Your camera may not have warnings for slow writing data rate speeds, and you may only realize frames have been dropped in post. By this time, it’s too late.
Data storage will also take a hit, especially if you are recording in memory heavy ProRes, DNxHD, or raw formats. A minute of UHD (3840x2160) footage in the ProRes 422 format will consume approximately 5GB of data. And if you’re charging for the work, then you’ve got to be backing it all up, effectively doubling the storage requirements.
You will notice that playback in your NLE software such as Premiere Pro demands more from your processor. Premiere Pro offers a streamlined workflow for creating and working with proxy files, but creating these files will take a bit of time and add an extra step to your workflow. When you have edited your video you can then swap back in the original 4k files for grading.
You can alternatively use the resolution option in the program monitor so the footage will play back at ¼ or 1/8 of the resolution when editing. But this fills your cache quickly. In my experience, I have found more success creating proxy files instead for smooth playback whilst editing. This is very important for me personally since much of my work is shooting and editing music videos, so realtime playback is needed to sync up cuts.
Also, be aware that 4k exporting is also going to take longer than a 1080p export. This will get especially frustrating if there are several niggly rounds of revisions towards the end of a project from the client.
Cameras such as the Panasonic GH5 will shoot a multitude of various frame rates to add some serious slow motion capabilities to your footage. But this is severely limited when shooting in 4k. The GH5 can shoot up to a whopping 180fps in 1080p, but just 60fps in 4k. Many other high end consumer mirrorless cameras such as the Sony A7s II will only shoot 30fps in 4k.
If you don’t need slow motion footage and have plenty of hard drive space, then 4k is surely the way to go right? Well yes and no, as there is one last huge benefit of a 1080p export.
Shooting in 4k for a 1080p output will give you the ability to crop your footage. This has a whole host of uses, such as the ability to add pans across your footage in post, or even having a faux second camera angle for an interview, one wide, one tight. Shooting in 4k for 1080p output opens up the floodgates to a whole host of creative tools which is simply not available in 4k unless shooting at 6k or 8k with something like the Red Weapon 8k that starts at $50,000.
Know Your Client
The technical limitations and changes in workflow are important to consider, but before all this, find out how your video will be delivered. If it is a promotional video for a small business to use on social media, there is no reason to shoot 4k. Save yourself the time and hard drive space. Alternatively, if you are shooting a wedding video that you know will be played on your client’s 60 inch 4k television, then shooting in 4k is worth serious consideration to really make your footage shine.
Price it Up
If it is not necessary, the benefit of shooting in 4k is that it’ll future proof your work. There may be an occasion when a client gets in touch a few years after completion to ask if there is a 4k version, and if there is, you can charge for it. It’ll also mean you can use the footage if you are making a 4k showreel of your work.
Shooting in 4k demands more of your time and investment into the video project, so make sure you are charging clients for the privilege to at least cover your extra costs. If you are eating up 5GB of data a minute, a 1TB hard drive isn’t going to last too long. And the extra steps in your workflow may add a few hours in post.
Let's not forget the cost of investment into high end consumer cameras that have 4k abilities. The Panasonic GH5, that shoots internal 4k 30p in 10bit 4:2:2, is priced at $1,997.99 for example. If you wanted to shoot 4k 60p in 10bit 4:2:2 then you are going to need an external monitor/recorder like the brand new Atomos Ninja Inferno, $995, along with some batteries and SSD drives As a fulltime videographer or filmmaker, cost of time and capital investment is vital to consider before any project is priced up, so make sure the extra resources are covered in your quote.
Lastly, 4k production should be seen as a premium product, in my opinion. If you have the gear, the skills and the processing power to push out really great looking 4k content, then charge a premium for it.
Storage these days is so cheap these days. I just default to shooting everything at 4k or higher-even if the client wants a 2k master file. This "future proof" concept is no longer a concept since you go to any Best Buy/TV store all you'd find are 4k TVs, I rarely if ever see 1080p TVs for sale or cameras announced these days. 4k is already here, distribution and acquisition rates in 4k goes higher each year so there's not much of a point kicking this 1080p dead horse around anymore.
It's also the efficiency of whatever your recording at. For example, if I was shooting a 24p ProRes 422 HQ (10bit) in UHD the bitrate is 88.4 MB/s. Compared to my Red which a 24p 6k 16x9 R3D file at the goto compression I use 7:1 it's 91.6 MB/s. So to get about twice as many pixels/resolution the file sizes are about the same in this case. To put things in perspective 8k R3Ds in 16x9 are 174.25 MB/s in the same 7:1 compression and is totally usable in 12:1 at 101.65 MB/s thanks to the more efficient compression of the Weapons.
You said it yourself, if you have a computer which can't adequately edit 4k then there's proxies. You did a great job listing the benefits of 4k, no sense setting the bar lower now.
Some may scoff at this process, especially those filming cinema stuff, but I do documentary work and it works awesome for me: using the 5D IV I record a ton of interviews and b-roll and what not in 4K, then when I get back I drop the clips from the memory card into Media Encoder and render them all out as h.264, which takes very little time. I get tiny (relative) files and minimal noticeable quality loss, imperceptible when I render the final video in HD.
Doing this gives me the versatility to crop, move, stabilize if needed, grade better and have 4K masters the same size as HD .MOV's straight out of camera. The files also playback fine in Premiere (on an iMac and MacBook Pro)
Could be because I'm in a smaller city, but I've yet to have a client NEED the final output in 4K. So by offering a much higher visual quality image, being able to use the whole 4K selling point, and it being pretty convenient, I've been able to up my pricing a lot move on up.
We just shot 4K for the first time yesterday and we had to build proxy files to edit it smoothly from our server. It certainly wasn't a quick edit.
Just be sure to know what your specific camera does when shooting in 1080 vs 4K (cropping the sensor, downscaling, you get it). Real world example is my 1DXII. At full 4K it is downright gorgeous footage; takes the C300 Mark II and straight curb stomps it. In FHD, on the other hand... It's terrible. Nothing like the 1DC's Super 35 mode.
The 1DXII shoots to CFast. I bought several 64gb cards but even at the monstrous 500mb/s speeds I rarely go through one; just shoot like you're shooting onto film (interviews require a more conservative approach but they should be hidden, for the most part, beneath b-roll anyway). Long story short, unless you are categorically pressed for space then shoot 4K and downscale in post.
If card space is the issue (which, with CF, it shouldn't be) then ingest your footage using something like Prelude or go straight to a color platform like Davinci and transcode it into something more manageable. If you don't believe me then scoot on over to Youtube and watch a video in both 1080 and 4k. Odds are your display isn't 4K but, in spite of that, you will absolutely notice a profound difference.
Just an innocent question, what resolution do theater projectors display at typically? I'm not trying to be a smart ass. I am just thinking about the 4k question.