Blueprint - looking back camera

Hi everyone.
I’m trying to implement a camera which points backward when I press a key.
One popular example is given by Outlast.
Ok, so I use a ThirdPersonCharacter on which the Camera is son of Mesh in order to set the head as parent socket and enabling the yaw on the ThirdPersonCharacter and UsePawnControlRotation on Camera.
Everything works fine except the looking back action.
This is my BP:

These are my camera settings:

138902-screen+shot+2017-05-23+at+17.32.01.png

138904-screen+shot+2017-05-23+at+17.36.28.png

and these are my ThirdPersonCharacter settings:

138907-screen+shot+2017-05-23+at+17.38.12.png

So, what’s the problem?
When I press “R” instead of looking back, my Player looks down. When released, he looks up, moreover he remains fixed looking up to the sky.
I’ve tried many different combo, but nothing seems to be working.
What do you thing I am doing wrong?
Thank you very much!

Out of my mind when you remove the camera from the boom in the thirdpersoncharacter to have a “realistic” fpcharacter, the camera is rotated by 90 degree. Check it out and if it is set the rotation to 0

Yes, I already did it just after setting up the camera.

So, after pressing R camera shouldn’t move or rotate, only point to (last rotation - 180) yes?

Try to start from something like this:

Pressed

pawn.use control rotation yaw = false →

camera.use pawn control rotation = false →

NewRotation = (Camera.get world rotation.Pitch, Camera.get world rotation.Yaw +180, Camera.get world rotation.Roll) →

CameraRotation.set world rotation (NewRotation)

Released

pawn.use control rotation yaw = true →

camera.use pawn control rotation = true