iPhone 7/Plus iPhone 7 Plus 4K video recording lag

[Nisaja]

Has anyone noticed how laggy the viewfinder gets when recording 4K video? It doesn’t happen all the time though. Closing the camera app and opening again fixes it. I’m on iOS 11.2 btw.

 

[jav6454]

Recording 4k is a tasking job on the CPU. The bitrate itself is high enough. Also, if your memory is full (RAM), it might slow down the process a bit to see the lag you describe.