1080p vs 4k video, the differences and what should you film at in 2019.
There are actually 2 resolutions for 4k; 3840 x 2160 which is tv and internet then there is 4096 x 2160 which is movie production “4k”. 1080p only has one general resolution for the 16:9 aspect ratio.
1080p is 1920 pixels wide by 1080 pixels in high.
4k is 3840 pixels wide by 2160 pixels high.
According to toolstud.io 60 seconds of 1080p at 60fps is 6.22MB big whilst 4k at 30 fps is 24.9MB.
4k is two times the resolution of 1080p but 4 times the size…. See this diagram as to why
The blue of 1080p can fit 4 times into the (orange) outline of 4k.
4 times the detail
4k video fits more detail due to the simple amount of more pixels it has over 1080p, you can also downscale 4k into 1080p to get a crisper looking footage than if you had of just filmed in 1080p.
Filming in 4k also gives you the advantage of cropping if you export as 1080p. You can shape the frame more and get creative with your transitions and effects.
Downsides for 4k include the much larger file size for both raw footage and exported. Again the more detail or video data needed for the larger resolution makes 4k files very big. You cannot really heavily compress 4k either because it will show whilst the smaller resolution 1080p can be heavily encoded at a lower bitrate (4mbps) and still look decent.
More resources needed
Editing 4k at times can be very taxing on your computer unless you’re running a fast multi cored machine with a beefy graphics card it’s going to be choppy. Editing 4k on a laptop without proxies would be borderline impossible. These issues wouldn’t be seen with 1080p.
Should you still film and edit in 1080p?
1080p is fine even in 2019 however if you have 4k filming capabilities they should be utilised in my opinion. 4k at 30fps is fine for most shots however action and the need for slows needs 60fps plus. Mixing 4k 30fps and 1080p 60fps/120fps is a decent option. I just don’t see the reason as to stick at 1080p if you can film 4k. Think of the future proofing, sure 4k will be “out” in a few years time when 6k and 8k pick up but the 4k time is truly now.