This post shows you how to change the video resolution on both the V3 and V4 UpAir One.
On the latest UpAir One (V4 with PX4 board) it’s different from the V3 (APM Board)
UpAir V4 (Pixhawk Powered)
You need to hold down the photo Button, it will Take a Photo, but afterward read 2.7k instead of 4k in the top left corner. Do it again and it will change to 1440.
It could be that the resolution doesn’t change after the first try, try it again and it will change.
It is not a matter of holding the button 5 seconds, sometimes it can take a long time for it changes resolution, but it works! this depends on the drone itself, for yours it can be done in a few seconds, but for someone else it can take up to a minute… be patient with this.
UpAir V3 (APM Powered)