The bug
As of snapshot 17w43a, when pressing the key assigned to Toggle Cinematic Camera, it's not possible to control the camera.
How to reproduce
Assign a key to Toggle Cinematic Camera
Press it
Move your mouse
Linked issues
is duplicated by 4
MC-121336
When the Cinematic Camera is enabled the mouse sensitivity goes to 200% and when it's not the sensitivity goes down.
Resolved
MC-121384
When using cinematic mode, camera is super sensitive
Resolved
MC-121409
Cinematic Mode is very glitchy.
Resolved
MC-121474
Cinematic Camera Movement Bug
Resolved
Comments 5
When setting the mouse sensitivity to 5%, I have discovered that cinematic mode does the gliding thing where it makes your mouse movement smoother, but it also only does so while your mouse is in motion. It will stop moving when your mouse stops moving. So it seems we have two issues: Mouse movement is hyper-sensitive when in cinematic mode, and it stops moving altogether when your mouse stops moving.
Can confirm.