CameraUI video recording blurred

I'm using the cameraUI class for letting users record a video. Unfortunately the result is barely useable because most of the time the video is between slightly blurred to completely blurred (particularly on some android device. It seems that while the exposure react correctly, the focus is off most of the time.

The problem is apparent on all the devices I tried be it iOS or android, but more dramatic on android. The definition of the video doesn't seem to be the culprit because touching the screen makes it better but for a very short period.

Anyone is using cameraUI for video recording?

Any help?

Thank you