1. Tap Settings.  2. Scroll down. 
  2. Tap Photos & Camera. 
  3. Tap 1080p at 30 fps next to Record Video. 
  4. Tap 4K at 30 fps.  Now when you return to the camera app and set it to shoot video, you’ll be recording in 4K. Note: One minute of 4K video will take up 375 MB of storage space. The lowest setting (720p at 30 fps) will take up just 60MB for one minute of footage. 

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