Producing television content in 4K UHD (Ultra High Definition) means you have a few more things to think about compared to a standard HD production. 4K UHD content delivers stunning results, whether you’re future proofing your assets or already delivering full 4K UHD final shows. But shooting 4K UHD can be a little more complex than a HD production and a little more expensive, adding anything up to around 35% onto the production budget.
Many of today’s cameras can shoot 4K but your choice of camera, as always, should be dictated by your budget, workflow and final deliverables. If money is no object and you have a large crew and plenty of time in post, shooting with the Arri Alexa 65 or Sony F65 enables you to capture some of the highest quality pictures possible. Here’s an overview of the most widely used cameras at different price points and some observations that might help your choice:
Dominating the middle ground are the two most popular hire cameras in their class: the competitively priced Sony FS7 and the Canon C300 Mk II (the follow-up to arguably the most successful broadcast camera of the past half decade). Both shoot in 4K and are good options for mid-range broadcast projects.
At the lower end of the market, the Sony A7S and Panasonic GH4 provide exceptional image quality, particularly for macro work. Both also have the added benefit for fast-paced Movi and grip shots and shooting in tight spaces. Their sensors are exceptionally sensitive in low light too. However, both cameras are limited in scope when thinking about lens options. Amazing value for money, but limitations mean they aren’t always well suited for use as the main camera for 4K and 4K UHD projects.
Lenses are as important a consideration as cameras when shooting 4k. Lens choice should both be dictated by budget and your desired final look. Vendors have made a big thing about ‘4K glass’, but by and large, this is simply marketing speak. The issue here is how fast the lenses are for light to travel through to reach the sensor. The lower the T number, the better, with zooms generally having a handicap in this regard. The lens adaptor (for example PL to EF) also makes the lens a stop or two slower.
4K UHD is very unforgiving of poor camera work and a slightly out of focus shot will scream at you from the post suite. So, ensure you have a very good DoP or camera operator.
Another issue aggravated when shooting 4K UHD at 25fps is stepping, where the additional resolution only intensifies the juddering movement of straight lines when panning or zooming.
Producers who have shot 4K UHD also comment on how the additional super-vivid resolution can be distracting or simply provides ‘too much information’. Considerations have to be made regarding better set design, make-up and how your subjects are shot, particularly in close-up.
Even in 4K UHD, you are still making numerous compromises from shoot to final delivery. This is worth thinking about ahead of filming. Having consulted with us and your post house, you might want to run some camera tests to check out various workflows and recording options. For example, if shooting on the Sony F55, the AXS R5 RAW recorder delivers a far crisper, cleaner image than shooting on SxS cards recording 4K XAVC in camera.
With 4x the resolution, you need 4x the media and storage. An FS7 shooting on a 128GB card can only record around 40 minutes 4K XAVC, which is a pretty compressed 4K image. With the AXS-R5 at minimum compression (2.4GB/s), the shooting time on a 512GB card is only 20 minutes.
Using media cards, as you might have used tape on a long shoot, is not an option due to it being too cost prohibitive. So you have to copy your rushes across and back them up at the end of the day’s shoot and someone needs to be responsible and accountable for this.
Viewing your 4K rushes in 4K UHD when mastering is, of course, desirable, but the majority of Soho post houses don’t yet have 4K monitoring. They tend to charge a premium for 4K suite work with additional charges again for 4K ingest, export and final file deliverables. A typical compositing or grading session will also add time and money because the render times are a lot longer. You’ll not only want a Grade 1 monitor (like the Sony BVM-X300) but you’ll also want a 4K UHD television to see what it looks like on a consumer set. The Grade 1 monitor tends to mislead with the very best colour and resolution reproduction, so you might find your production looks a little disappointing when later seen on a consumer 4K UHD television.
Doing as much in-house ahead of going into a post house is highly recommended. You can edit and playback 4K content on a reasonably powerful home desktop or even laptop, using standard editing packages such as Adobe Premiere, Apple FCP X and Avid Media Composer. This is an invaluable way to keep your post costs under control. From Red 6 and 8K, you can reframe, crop, zoom and create your own 4K UHD passes.