Reality Check: What Does a 4K Production Workflow Require?

When people talk about 4K, it sounds like an incredible thing: four times the size of HD, or more! The Digital Cinema standard (DCI) is more than 8 million pixels--4096×2160. The Ultra High Definition standard (UHD, also called QuadHD) standard is also over 8 million pixels, but with slightly less width--3840×2160. You can shoot 24p or 30p, and some high end cameras can shoot even higher frame rates that you can convert to slow potion in post.

4K specs courtesy of Wikipedia

Do you need a new "mega" PC to edit 4K? Do you need a $9,000 Mac Pro, Thunderbolt-2 RAID, and more to adequately handle 4K? Do you need the fastest media cards, like the new UHC-3 SDXC cards? Probably not. Delve deeper into the specifics of your production chain, and do a little math, to find out what your needs really are.

4K requirements per Mac hard drive-maker LaCie

4K Here and Now

The time for idle speculation about 4K production has passed. There are many cameras that can shoot 4K now. 4K is already an inevitable part of the professional video workflow. 4K-ready cameras run the gamut, from the Samsung Galaxy Note III phone ($200 on contract), to the GoPro Hero3+ Black Edition ($400), to the Panasonic GH4 ($1,700), to the Sony FDR-AX100 consumer handicam ($2,000), to the Blackmagic Design Production Camera 4K ($3,000), Sony FDR-AX1 ($4,500), Sony PXW-Z100 ($5,500) and on up to many tens of thousands of dollars.

Searching for 4K cameras reveals the range of options and price points.

Not all 4K is created equal, quality-wise; you shouldn't expect the 100 Mbps stream recorded by the Panasonic GH4 to deliver the same quality 4K as the 600Mbps stream recorded by Sony's PXW-Z100. Some of the higher-end cameras, not even mentioned here, record 5 and 10x the amount of information in a RAW format so that there is more visual information available in postproduction.

Video capture data rates comparisons from Sony

If you're shooting with cameras that cost well under $10,000, your data rates will most likely come in under 200 Mbps, unless you'rer working with the Blackmagic Design 4K camera, which records 880 Mbps ProRes. The Sony FDR-AX1 records UHD 4K at 150 Mbps; the Panasonic GH4 records UHD and DCI at 100 Mbps. The Sony AX100, GoPro, and cell phones go lower still. And producers have said many good things said about the quality of 4K captured at those data rates.

How is effective 4K at sub-100 Mbps data rates possible? While the number of pixels has indeed quadrupled compared to HD, the complexity of the image, generally, has not. An HD talking head is still a talking head at 4K. And with larger sensors, much of the scene will have a soft focus blur to it, which is very easy to compress. Is there a wall, a floor, sky or something large and flat? Well that's a huge hunk of pixels that can be grouped together. In fact, with 4K, it's a massive amount of pixels that can be easily compressed.