With the release of drones such as the Inspire 1 and Phantom 3, 4K and UHD aerial video have entered the mainstream. There has been a lot of debate over the necessity of these higher-resolution formats, but make no mistake- shooting in 4K or UHD opens up a world of possibilities when it comes time for post-production.
4K and UHD refer to two slightly different resolution standards, though the terms are often (incorrectly) used interchangeably. True 4K resolution is 4,096 by 2,160, while UHD is 3,840 by 2,160. Very few TVs or monitors are truly 4K- most are UHD, regardless of the advertising. For this reason, we work primarily with UHD- our audience is unlikely to be able to view full 4K anyway.
The most obvious benefit of UHD is in the increased detail- roughly four times as much as standard 1080p resolution. On larger displays, or from close viewing distances, that additional definition makes a real difference. Critics of UHD are quick to point out that on smaller displays, or viewed at a distance, the jump in resolution from 1080p is unnoticeable. There is some truth in this- your eyes likely cannot perceive the additional detail under those circumstances.
However, shooting in UHD is not necessarily about displaying your final product in UHD. You can increase the quality of a 1080p video export by shooting in 4K and downscaling from there. Even if you never intend for your video to be viewed in UHD, your videos will look better if you shoot in UHD and then scale. Without getting too technical, this is due to chroma sub-sampling; the additional color information you gain from shooting in 4K is retained in the 1080p conversion.
UHD also gives you more flexibility in the editing process. You can use it as a 4x digital zoom, and still maintain 1080p resolution. Particularly for aerial work, this is a handy tool; you don’t need to get quite as close to your subject. UHD also allows you plenty of room to crop your shots in post as well.
Each frame of a UHD video is around 8-megapixels. These stills are high enough resolution to be used as photos, as long as you’re not going to make large prints. This means your camera is essentially taking 24, 30, or even 60 8-megapixel photos per second. You’re pretty unlikely to miss the shot with that kind of rapid-fire. Think of UHD as a crazy burst photography option.
The downside: working with UHD footage is incredibly computer-intensive. The 5K iMac is the only consumer-grade computer equipped to handle the task, and even then you will likely run into thermal throttling issues. A better option would be a Mac Pro or a Windows workstation alternative- these computers are specifically designed for intensive video production tasks, and have cooling solutions that will allow your internal components to run at full speed. Expect to spend significantly more on your computer than on your drone to enjoy a smooth editing experience.
Bear in mind that specs never tell the whole story. A 4K or UHD camera is not inherently better than a 1080p camera. The size and quality of the sensor matter more than the raw numbers. All else being equal, shooting at higher resolutions will make your videos look better. If you’ve got the hardware, you’ll certainly appreciate the extra definition in post.