Yi 4k Things specific to the yi4k. Ultra Increased Resolution Mod A script that increases the resolution of the 4k ultra mode to 4000x2700 and the 1080p 90p ultra mode to 2000x1500. For older firmwares see: 1.7.17 1.7.8 1.6.1 1.5.1 1.4.23 1.4.14 1.4